0001193125-26-197184 | 20-F | XBRL Viewer | Silicon Motion Technology Corp

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Major customers representing at least 10% of net sales (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenue, Major Customer [Line Items]
NET SALES	$ 885,627	$ 803,552	$ 639,142
Net sales \| Customers accounted for 10% or more \| Micron
Revenue, Major Customer [Line Items]
NET SALES	$ 86,201	$ 151,780	$ 144,011
Major customers, percentage of net sales	10.00%	19.00%	22.00%
Net sales \| Customers accounted for 10% or more \| Kioxia
Revenue, Major Customer [Line Items]
NET SALES	$ 105,704	$ 119,727
Major customers, percentage of net sales	12.00%	15.00%
Net sales \| Customers accounted for 10% or more \| SK Hynix
Revenue, Major Customer [Line Items]
NET SALES			$ 75,836
Major customers, percentage of net sales			12.00%
Net sales \| Customers accounted for 10% or more \| PHISEMI
Revenue, Major Customer [Line Items]
NET SALES	$ 216,456	$ 107,407
Major customers, percentage of net sales	24.00%	13.00%
Net sales \| Customers accounted for 10% or more \| AFASTOR
Revenue, Major Customer [Line Items]
NET SALES	$ 104,248	$ 82,678	$ 70,046
Major customers, percentage of net sales	12.00%	10.00%	11.00%

Shareholders' Equity

12 Months Ended

Dec. 31, 2025

Federal Home Loan Banks [Abstract]

Shareholders' Equity

12. SHAREHOLDERS’ EQUITY

Dividends

The Company’s quarterly dividends are as follows:


	2023				2024				2025
	Dividends Per Share (US$)		Amount (in US$ thousand)		Dividends Per Share (US$)		Amount (in US$ thousand)		Dividends Per Share (US$)		Amount (in US$ thousand)
First quarter	$	—	$	—	$	0.1250	$	16,841	$	0.1250	$	16,988
Second quarter		—		—		0.1250		16,843		0.1250		16,779
Third quarter		—		—		0.1250		16,844		0.1250		16,781
Fourth quarter		0.1250		16,708		0.1250		16,846		0.1250		16,781

			$	16,708			$	67,374			$	67,329

On November 2, 2015, the board of directors adopted a policy to declare the annual dividend to be paid in four quarterly installments. On October

30, 2023, October

28, 2024 and October 27, 2025, the board of directors declared annual dividends of US$2.0

, US$2.0

and US$2.0 per ADS, equivalent to US$0.5

, US$0.5

and US$0.5 per common share, to be paid in four quarterly installments. Future dividends, if any, will be declared by and subject to the discretion of the Company’s board of directors.

Share Repurchase

On February 6, 2025, the board of directors of the Company authorized the repurchase of up to US$50 million of the Company’s ADSs over a

6-month

period.

For the year ended December 31, 2025, the Company repurchased 426 thousand ADSs at a total cost of US$24,312 thousand. The weighted average purchase price per ADS repurchased was US$57.04. The authorized repurchase program was completed in August 2025.

- Definition

The entire disclosure for equity.

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+ Details

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 122,635	$ 89,249	$ 52,873
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX EFFECT OF NIL
Change in net foreign currency translation adjustments	1,001	(815)	(1,694)
Change in deferred pension gain	0	0	252
OTHER COMPREHENSIVE INCOME (LOSS)	1,001	(815)	(1,442)
TOTAL COMPREHENSIVE INCOME	$ 123,636	$ 88,434	$ 51,431

- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-4

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(21))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(23))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482739/220-10-55-15

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A

+ Details

Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Current taxes:
Hong Kong taxes — current	$ 1,728	$ 5,428	$ 3,983
Foreign taxes — current	15,937	13,154	3,764
Total current taxes	17,665	18,582	7,747
Deferred taxes:
Hong Kong taxes — deferred	0	0	0
Foreign taxes — deferred	(173)	(422)	428
Total deferred taxes	(173)	(422)	428
Income tax expense	$ 17,492	$ 18,160	$ 8,175
Effective tax rate	12.50%	16.90%	13.40%

Income Taxes

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Income Taxes

11. INCOME TAXES

Income Tax Provision

Income before income tax is comprised of the following:


	Year Ended December 31
	2023			2024			2025
	US$			US$			US$
Cayman		(17,082	)		(5,305	)		(21,802	)
Income recorded in Hong Kong		23,741			34,983			14,208
Income from other foreign operations		54,389			77,731			147,721

Income before taxes		61,048			107,409			140,127

The components of income tax provision (benefit) were as follows:


	Year Ended December 31
	2023			2024			2025
	US$			US$			US$
Current taxes:
Hong Kong taxes — current		3,983			5,428			1,728
Foreign taxes — current		3,764			13,154			15,937

Total current taxes		7,747			18,582			17,665
Deferred taxes:
Hong Kong taxes — deferred		—			—			—
Foreign taxes — deferred		428			(422	)		(173	)

Total deferred taxes		428			(422	)		(173	)

Income tax expense		8,175			18,160			17,492

Effective tax rate		13.4	%		16.9	%		12.5	%

Effective Tax Rate Reconciliation

The Company adopted ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, on a prospective basis. The Company consists of a Cayman Islands parent company with various foreign and U.S. subsidiaries. Under the current laws of Cayman Islands, the Company is not subject tax on its income. The Company conducts its core business activities across East Asia, including China, Hong Kong, Macau, and Taiwan. The Hong Kong statutory income tax rate of

16.5%

reflects the Company’s economic and administrative center and most closely approximates the Company’s effective tax rate across its principal operating jurisdictions. While applicable statutory tax rates vary among these jurisdictions and may be subject to preferential regimes or adjustments, management believes that the Hong Kong statutory income tax rate provides the most representative measure of the Company’s overall tax profile. Accordingly, for purposes of reconciling statutory tax rate to effective income tax rate pursuant to ASU 2023-09, the Company has evaluated and determined to apply Hong Kong statutory tax rate of 16.5%, starting from 2025. The statutory tax rates in the jurisdictions the Company operates range from

12% to 21%. For the year ended December 31, 2025, the Company’s effective tax rate was 12.5%, a decrease from 13.4% and 16.9% in 2023 and 2024, respectively,

primarily due to changes in the proportional income earned by operations in key jurisdictions. Effective tax rates in each jurisdiction are generally lower than statutory rates due to tax credits for research and development and other tax incentive programs and

are

determined by different government policies in each of the jurisdictions where the Company operates.

A reconciliation of the Hong Kong statutory rate of 16.5% to the Company’s effective tax rate for the year ended December 31, 2025 was as follows :


	2025
	US$			%
Tax at Hong Kong Statutory Rate		23,121			16.5
Other Jurisdiction Tax Effects
Cayman Islands
Statutory tax rate difference between Hong Kong and Cayman Islands		(3,482	)		(2.5	)
Nontaxable or nondeductible items		7,078			5.1
Other		290			0.2
Macau
Statutory tax rate difference between Hong Kong and Macau		(2,075	)		(1.5	)
Other		(131	)		(0.1	)
China
Statutory tax rate difference between Hong Kong and China		3,154			2.3
Tax Credits		(4,825	)		(3.4	)
Changes in Valuation Allowances		762			0.5
Other		(202	)		(0.1	)
U.S.
Statutory tax rate difference between Hong Kong and U.S.		(1,855	)		(1.3	)
Changes in Valuation Allowances		2,589			1.9
Other		31			0.0
Other Foreign Jurisdictions
Statutory tax rate difference between Hong Kong and Other Foreign Jurisdictions		1,046			0.8
Other		638			0.5
Changes in Unrecognized Tax Benefits		(8,647	)		(6.2	)

Provision for income taxes and effective tax rate		17,492			12.5

A reconciliation of the Company’s income tax expense at Cayman statutory rate and provision for income tax prior to adoption of ASU 2023-09 is shown below:


	2023			2024
	US$			US$
Tax expense at Cayman statutory rate		—			—
Differences between Cayman and other statutory tax rates		9,979			16,107
Permanent differences		206			365
Temporary differences		(1,614	)		(2,703	)
Alternative minimum tax		1			1
Income tax on undistributed earnings		—			193
Net changes in income tax credit		(205	)		(101	)
Net changes in valuation allowance of deferred income tax assets		3,260			5,014
Net operating loss carryforwards		(1,805	)		497
Liabilities related to unrealized tax benefits		5,482			(42	)
Adjustment of prior years’ taxes and others		(7,129	)		(1,171	)

Income tax expense		8,175			18,160

Income Taxes Paids

The following table presents income taxes paid, net of refunds received, for the year ended December 31, 2025.


	Year ended December 31, 2025
	US$
Hong Kong		5,729
Macau		10,078
Others		906

Total income tax paid, net of refunds		16,713

Deferred and Current Income Taxes

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts for income tax purposes.

Significant components of our deferred tax assets (liabilities) at the end of each period are as follows:


	December 31
	2024			2025
	US$			US$
Stock-based compensation		1,520			3,090
Allowance for sales return		1,024			472
Inventory reserve		3,122			1,939
Foreign currency translation		(126	)		7
Property and equipment		(628	)		(568	)
Investment tax credits		3,596			3,603
Net operating loss carryforwards		21,607			24,636
Others		6,563			7,228
Valuation allowance		(27,800	)		(31,356	)

Net deferred tax assets		8,878			9,051

The valuation allowance shown in the table above relates to net operating loss carryforwards, tax credits and temporary differences for which the Company believes that realization is uncertain. Valuation allowance increased by US$4,680 thousand and US$3,556 thousand for the year ended December 31,

2024 and

2025, respectively. The increase in valuation allowance in 2024 and 2025 had been based on all information

that is currently available

, particularly the earnings history and forecasts of future taxable income in each respective jurisdiction.

As of December 31, 2025, the Company’s U.S. federal net operating loss carryforwards for federal income tax purposes were approximately US$23,605 thousand as of December 31, 2025, expiring at various times starting from 2026 through 2037 for federal losses generated through December 31, 2017, if not utilized. As a result of the U.S. Tax Cuts and Jobs Act (TCJA), all federal net operating losses of US$27,848 thousand that are generated beginning January 1, 2018 and beyond will carryforward indefinitely.

As of December 31, 2025, the Company’s U.S. federal and state research and development tax credit carryforwards for federal and state income tax purposes were approximately US$2,205 thousand and US$1,398 thousand, respectively. If not utilized, the federal tax credit carryforwards will expire starting in 2045, while the state tax credit carryforward has

expiration date in California.

Current U.S. federal and California state laws include substantial restrictions on the utilization of net operating losses and credits in the event of an “ownership change” of a corporation. Accordingly, the Company’s ability to utilize net operating loss and tax credit carryforwards may be limited as a result of such “ownership change”. Such a limitation could result in the expiration of carryforwards before they are utilized.

As of December 31, 2025, the Company had accumulated undistributed earnings from a foreign subsidiary of US$569 million. No deferred tax liability was recorded in respect of those amounts as these earnings are considered indefinitely reinvested. It is not practicable to estimate the amount of unrecognized deferred tax liabilities for these undistributed foreign earnings.

Unrecognized Tax Benefit

A reconciliation of the beginning and ending balances of the total amounts of unrecognized tax benefits is as follows:


	Year Ended December 31
	2023			2024			2025
	US$			US$			US$
Balance, beginning of year		37,105			43,764			43,584
Increases in tax positions taken in current year		16,054			4,376			6,328
Decrease in tax position taken in prior year primarily related to the resolution of tax audit		(9,395	)		(4,556	)		(14,654	)

Balance, end of year		43,764			43,584			35,258

At December 31, 2025, the Company had US$35,258 thousand of unrecognized tax benefits that if recognized would affect the effective tax rate. For the year ended December 31, 2023 the total amount of interest expense and penalties related to uncertain tax positions recorded in the provision for income tax expense was approximately US$1,072 thousand. For the years ended December 31, 2024 and 2025, the Company derecognized approximately US$1,053 thousand and US$ 465 thousand, respectively

for the interest expense and penalties

previously

accrued because of a lapse in the statute of limitations. The total amount of accrued interest and penalties recognized as of December 31, 2024 and 2025 was US$6,797 thousand and US$6,332 thousand, respectively. The Company does not expect uncertain tax positions to change in the next twelve months, except in the case of settlements with tax authorities, the likelihood and timing of which are difficult to estimate.

The Company files income tax returns in the U.S. and foreign jurisdictions. The following table summarizes the Company’s major jurisdictions and tax years that remain subject to examination by tax authorities as of December 31, 2025:


Tax Jurisdiction		Tax Years
China		2022 and onward
Hong Kong		2022 and onward
Taiwan		2020 and onward
United States		2020 onward

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477617/942-740-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478822/944-740-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12C

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12B

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477891/740-270-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-13

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/740/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-14

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-21

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-17

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

Refund Liabilities (Tables)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Summary of Change in Refund Liabilities

The changes in the refund liabilities are summarized as follows:


	Year Ended December 31
	2024			2025
	US$			US$
Refund liabilities
Balance, beginning of year		3,329			5,968
Additions		5,209			1,838
Actual sales return and discount		(2,570	)		(1,794	)

Balance, end of year		5,968			6,012

Lease

12 Months Ended

Dec. 31, 2025

Leases [Abstract]

Lease

14. LEASE

Operating Leases

The Company entered into various operating lease agreements, which consist of real property and office equipment with lease periods expiring between fiscal years 2025 and 2033. The Company recognized leased assets in operating lease assets of US$14,674 and US$13,195 thousand and corresponding accrued expenses and other current liabilities of US$2,528 and US$2,586 thousand, and

other long-term liabilities

of US$12,413 and US$11,464 thousand, as of December 31, 2024 and 2025, respectively. The weighted average remaining lease term was 7.79 years and 6.94 years, and the weighted average discount rate was 2.49% and 2.43% as of December 31, 2024 and 2025, respectively.

The maturities of the operating lease liabilities as of December 31, 2025, were as follows:


	Operating Lease Obligations
Fiscal Year:
2026	$	2,887
2027		2,308
2028		1,788
2029		1,698
2030		1,698
2031 and thereafter		4,813

Total		15,192
Less imputed interest		1,142

Present value of lease liabilities		14,050
Less operating lease liabilities-current		2,586

Long-term operating lease liabilities	$	11,464

Operating lease expenses for the years ended December 31, 2023, 2024 and 2025 are US$5,261 thousand, US$4,339 thousand, and US$4,165 thousand, respectively. For the supplemental cash flow information related to lease, the cash paid for amounts included in the measurement of operating lease liabilities was US$3,825 thousand, US$2,569 thousand and US$2,687 thousand for the year ended December 31, 2023, 2024 and 2025, respectively. The Company recognized

right-of-use

assets of US$13,823 thousand, US$3,198 thousand, and US$189 thousand upon entering into operating lease arrangements for the years ended December 31, 2023, 2024, and 2025, respectively.

Equity Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2025

Share-based Payment Arrangement [Abstract]

Summary of Stock Option and Restricted Stock Units Activity

The following is a summary of the 2015 Plan and the 2025 Plan, which includes restricted stock units:


	Unit (in Thousands)
Available for grant at January 1, 2023		9,580
Restricted stock units granted		(624	)
Restricted stock units forfeited		51
Available for grant at December 31, 2023		9,007
Restricted stock units granted		(1,225	)
Restricted stock units forfeited		18

Available for grant at December 31, 2024		7,800
Authorized-2025 Plan		20,000
Terminated-2015 Plan		(7,749	)
Restricted stock units granted		(1,460	)
Restricted stock units forfeited		24

Available for grant at December 31, 2025		18,615

Summary of Restricted Stock Units and Changes

A summary of the status of restricted stock units and changes is as follows:


	Number of Non-vested Stock Units (in Thousands)			Weighted Average Grant Date Fair Value (US$)		Weight Average Remaining Recognition Period (Years)
Non-vested at January 1, 2023		1,977			17.89		0.66
Restricted stock units granted		624			13.51
Restricted stock units vested		(1,460	)		18.36
Restricted stock units forfeited		(51	)		16.38

Non-vested at December 31, 2023		1,090			15.00		0.13
Restricted stock units granted		1,225			15.68
Restricted stock units vested		(1,089	)		14.94
Restricted stock units forfeited		(18	)		15.26

Non-vested at December 31, 2024		1,208			15.68		0.25
Restricted stock units granted		1,460			19.51
Restricted stock units vested		(1,186	)		15.63
Restricted stock units forfeited		(24	)		19.44

Non-vested at December 31, 2025		1,458			19.46		0.29

Stock-based Compensation Expense

The following table shows total stock-based compensation expense included in the Consolidated Statements of Income for the years ended December 31, 2023, 2024 and 2025.


	Year Ended December 31
	2023		2024		2025
	US$		US$		US$
Cost of sales		406		311		411
Research and development		11,709		11,284		17,874
Sales and marketing		1,858		1,954		3,428
General and administrative		3,574		3,407		4,570

		17,547		16,956		26,283

Segment Information - Additional Information (Detail)	12 Months Ended
Segment Information - Additional Information (Detail)	Dec. 31, 2025 Segment
Segment Reporting [Abstract]
Reportable segment	1
Number of operating segments	1

Long-Term Investments - Equity Investments with Carrying Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Schedule of Equity and Cost Investments [Line Items]
Long-term investments	$ 29,676	$ 17,326
Investment, Type [Extensible Enumeration]	Equity Securities	Equity Securities
Equity Securities
Schedule of Equity and Cost Investments [Line Items]
Long-term investments	$ 0	$ 6,500
Cashido Corp. (Cashido)
Schedule of Equity and Cost Investments [Line Items]
Equity Investments Percentage of Ownership	0.00%	0.00%
Vastview Technology, Corp. (Vastview)
Schedule of Equity and Cost Investments [Line Items]
Equity Investments Percentage of Ownership	0.00%	0.00%
Kinara, Inc (Kinara)
Schedule of Equity and Cost Investments [Line Items]
Long-term investments	$ 0	$ 6,500
Equity Investments Percentage of Ownership	0.00%	12.00%
BIWIN Storage Technology Corp. (BIWIN) \| Equity Securities
Schedule of Equity and Cost Investments [Line Items]
Long-term investments	$ 11,432	$ 6,034
Equity Investments Percentage of Ownership	0.00%	0.00%
Shenzhen Techwinsemi Technology Corp (TWSC) \| Equity Securities
Schedule of Equity and Cost Investments [Line Items]
Long-term investments	$ 18,244	$ 4,792
Equity Investments Percentage of Ownership	0.00%	0.00%

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Basis of Presentation

The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The consolidated financial statements include the accounts of SMTC and its wholly-owned subsidiaries. The Company owns 100% of the outstanding shares in all of its subsidiaries. All significant intercompany balances and transactions have been eliminated upon consolidation.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect certain reported amounts and disclosures. The actual results could differ from those estimates.

Concentration of Credit Risk and Significant Customers

Financial instruments that potentially subject the Company to a significant concentration of credit risk consist principally of cash equivalents and accounts receivable. Cash and cash equivalents are maintained with high quality financial institutions, the composition and maturities of which are regularly monitored by management. The Company believes that the concentration of credit risk in its accounts receivable is substantially mitigated by the Company’s credit evaluation process, relatively short collection terms and the high level of credit worthiness of its customers. The Company performs ongoing credit evaluations of its customers’ financial conditions and limits the amount of credit extended based upon the payment history and current credit worthiness of the customer. The Company regularly reviews the allowance for bad debt and doubtful accounts or expected losses during the accounts receivable collection process by considering factors, such as historical

write-off

and recovery experience, credit quality, age of the accounts receivable balances and current economic conditions that may affect a customer’s ability to pay. The Company also takes into account reasonable and supportable forecasts of future conditions when evaluating the adequacy of the allowance for doubtful accounts.

Historically, a relatively small number of customers have accounted for a significant portion of our net sales. Sales to three customers in 2023

four customers in 2024, and four customers in 2025 each accounted for 10% or more of our net revenue, representing 45%, 57% and 58% of our net sales in 2023, 2024 and 2025, respectively. In 2023, the significant customer

were SK Hynix, Micron and AFASTOR. In 2024, they were Micron, Kioxia, PHISEMI and AFASTOR. In 2025, they were PHISEMI, Kioxia, AFASTOR and Micron. The Company’s top ten customers in 2023, 2024 and 2025 accounted for approximately 75%, 84% and 82% of net sales, respectively.

Fair Value of Financial Instruments

The carrying amount of the Company’s financial instruments, including cash and cash equivalents, accounts receivable and notes and accounts payable, approximates fair value due to the short-term maturity of the instruments. Long-term investments in listed companies over which we do not exercise significant influence are recorded at fair value, and any changes in fair value are recognized in net income. Long-term investments in privately- held companies with no readily determinable market value are recorded using the cost method, since the cost of obtaining verifiable fair value is unreasonably high. These investments are measured at cost less impairment, if any, plus or minus any changes resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer. Any resulting change in carrying amount would be reflected in net income. The Company’s long-term liabilities approximate their fair values as they contain interest rates that vary according to market interest rates.

Fair value is the price that would be received upon sale of an asset or paid upon transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that assets or liability. The fair value should be calculated based on assumptions that market participants would use in pricing the asset or liability, not on assumptions specific to the Company. A three-tier fair value hierarchy is established as a basis for considering such assumptions and for inputs used in the valuation methodologies in measuring fair value. The hierarchy prioritizes the inputs into three levels based on the extent to which inputs used in measuring fair value are observable in the market. Each fair value measurement is reported in one of the three levels which is determined by the lowest level input that is significant to the fair value measurement in its entirety. These levels are:

Level 1 — Use unadjusted quoted prices in active markets for identical assets or liabilities.

Level 2 — Use observable inputs other than Level 1 prices such as quoted prices for identical or similar instruments in markets that are not active, quoted prices for similar instruments in active markets, and model-based valuation in which all significant inputs are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3 — Use inputs that are generally unobservable and reflect the use of significant management judgments and estimates.

The tables below set forth, by level, the Company’s assets and liabilities that are measured at fair value on a recurring basis. The tables do not include assets and liabilities that are measured at historical cost or any basis other than fair value:


	Fair Value Measurements at December 31, 2025
	Level 1		Level 2		Level 3		Total
Items measured at fair value on a recurring basis:
Assets
Long-term investments:
Marketable equity investments	$	29,676		—		—	$	29,676


	Fair Value Measurements at December 31, 2024
	Level 1		Level 2		Level 3		Total
Items measured at fair value on a recurring basis:
Assets
Long-term investments:
Marketable equity investments	$	10,826		—		—	$	10,826

The carrying value of investments in

non-marketable

equity securities recorded to fair value on a

non-recurring

basis is adjusted for observable transactions for identical or similar investments of the same issuer or for impairment. These securities relate to equity investments in privately-held companies. These items measured at fair value on a

non-recurring

basis are classified as Level 3 in the fair value hierarchy because the value is estimated based on valuation methods using the observable transaction price at the transaction date and other unobservable inputs such as volatility, rights and obligations of the securities held. As of December 31, 2024 and 2025,

non-marketable

equity investments had a carrying value of $6,500 thousand and nil, respectively, and are included in long-term investments on the Company’s consolidated balance sheets.

Cash Equivalents

The Company considers all highly liquid instruments acquired with a remaining maturity of

three months

or less when purchased to be cash equivalents. In addition, time deposits with maturities ranging from more than three months to one year qualify as cash equivalents because they can be readily converted into known amounts of cash without advance notice with the principal protected and not subject to penalty in an early withdrawal.

Allowance for Doubtful Accounts

An allowance for doubtful accounts is provided based on a review of the collectability of accounts receivable. The Company determines the amount of allowance for doubtful accounts by examining the historical collection experience, current trends in the credit quality of its customers and its internal credit policies as well as current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect a customer’s ability to pay.

Inventories

Inventories are stated at the lower of cost or net realizable value for raw materials, work in process and finished goods. Inventories are recorded at standard cost and adjusted to the approximate weighted-average cost at the balance sheet date. The Company assesses its net realizable value of the inventory for estimated obsolescence or unmarketable inventory based upon management’s assumptions about future demand and market conditions. In estimating impairment losses for obsolescence, the Company primarily evaluates estimates based on the timing of the introduction of new products and the quantities remaining of old products and writes down for inventory on hand in excess of the estimated demand. Estimated losses on slow-moving items are written down below the current carrying value and included in cost of sales.

Long-term Investments

Investee companies over which the Company had the ability to exercise significant influence but did not have a controlling interest and was the primary beneficiary were accounted for using the equity method. Significant influence was generally considered to exist when the Company had an ownership interest in the voting shares of the investee between 20% and 50% and other factors, such as representation in the investee’s board of directors, voting rights and the impact of commercial arrangements, were considered in determining whether the equity method of accounting was appropriate.

Long-term investments in listed companies over which we do not exercise significant influence are recorded at fair value, and any changes in fair value are recognized in net income. If the Company does not have the ability to exercise significant influence over the operations of the investments in private-held companies, the Company accounts for the investment under the measurement alternative method. Investments in privately-held companies are subject to impairment review on an ongoing basis. Investments are considered impaired when the fair value is below the investment’s cost basis. This assessment is based on a qualitative and quantitative analysis, including, but not limited to, the investee’s revenue and earnings trends, available cash and liquidity, and the status of the investee’s products and the related market for such products.

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation. Significant additions, renewals and betterments are capitalized, while maintenance and repairs are expensed as incurred.

Depreciation is computed using the straight-line method over estimated useful lives that range as follows: buildings — 25 to 50 years; machinery and equipment — 2 to 6 years; furniture and fixtures — 3 to 8 years; software — 1 to 5 years; leasehold and buildings improvement — the shorter of the estimated useful life or lease term, which is generally 2 to 6 years. Land is not depreciated. Depreciation and amortization expense on property and equipment were approximately US$21,810 thousand, US$25,331 thousand and US$30,174 thousand for the years ended December 31, 2023, 2024 and 2025, respectively.

Lease

The Company determines if an arrangement is a lease at inception. Operating lease

right-of-use

(“ROU”) assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Operating lease ROU assets also include any initial direct costs and prepayments less lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. As the Company’s leases do not provide an implicit rate, the Company uses its collateralized incremental borrowing rate based on the information available at the lease commencement date, including lease term, in determining the present value of lease payments. Lease expense for these leases is recognized on a straight line basis over the lease term.

Impairment of Long-Lived Assets

The Company evaluates the recoverability of long-lived assets whenever events or changes in circumstances indicate the carrying value may not be recoverable. The determination of recoverability is based on an estimate of undiscounted cash flows expected to result from the use of an asset and its eventual disposition. The estimate of cash flows is based upon, among other things, certain assumptions about expected future operating performance, growth rates and other factors. Estimates of undiscounted cash flows may differ from actual cash flows due to, among other things, technological changes, economic conditions, changes to the business model or changes in operating performance. If the sum of the undiscounted cash flows is less than the carrying value, an impairment loss is recognized, measured as the amount by which the carrying value exceeds the fair value of the asset. Fair value is determined by reference to quoted market prices, if available, or discounted cash flows, as appropriate.

Other Assets

Other assets primarily consist of deposits for building construction and office leases.

Restricted Assets

Restricted assets consist of restricted cash and cash set aside as collateral for obtaining foundry capacity and the government grant restricted for research and development purposes.

Other long-term liabilities

Other long-term liabilities primarily consist of deposit

from construction in progress, noncurrent lease liabilities and unrecognized tax benefit.

Revenue Recognition

The Company recognizes revenue upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. Under the revenue recognition standard of Accounting Standards Codification Topic 606,

Revenue from Contracts with Customer (ASC 606),

the Company applies the following five-step approach: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when a performance obligation is satisfied.

The Company enters into contracts that may include products that are capable of being distinct and accounted for as separate performance obligations. To date, the majority of the revenue has been generated by sales associated with products, where a single performance obligation is identified in general. Revenue from services has been insignificant. Performance obligations associated with product sales transactions are generally satisfied when control passes to customers upon shipment or the written acceptance of the customers. Accordingly, product revenue is recognized at a point in time when control of the asset is transferred to the customer. The Company recognizes revenue when it satisfies a performance obligation by transferring control of a product to a customer in an amount that reflects the consideration to which it is entitled in exchange for those goods. Some of the Company’s sales are made to distributors and revenue is recognized when control of a product passes to the distributor upon shipment and terms and payment by the distributor are not contingent on resale of the product.

The Company grants certain distributors limited rights of return and price protection rights on unsold products. The return rights are generally limited to five percent of the monetary value of products purchased within the preceding six months, provided that the distributor places a corresponding restocking order of equal or greater value. An allowance for sales returns for distributors and all customers is recorded at the time of sale based on historical return information available, management’s judgment and any known factors at the time the financial statements are prepared that would significantly affect the allowance. Price protection rights are based on the inventory of products the distributors have on hand at the date the price protection is offered. Actual price adjustments to distributors incurred by the Company have been minimal.

The Company provides warranty for its products. Warranty returns have been infrequent and relate to defective or

off-specification

parts. The Company estimates a reserve for warranty based on historical experience and records this amount to cost of sales. For the years ended December 31, 2023, 2024 and 2025, the Company did not experience significant costs associated with warranty returns.

Research and Development

Research and development costs are expensed as incurred. Research and development expense consists primarily of personnel-related expenses, including stock-based compensation, as well as product masks, IP licensing, design tool and testing costs, equipment depreciation, amortization of intangible assets and an allocated portion of occupancy costs.

Income Taxes

The provision for income tax represents income tax paid and payable for the current year plus changes in the deferred income tax assets and liabilities during the years. Deferred income tax assets are recognized for net operating loss carryforwards, research and development credits, and temporary differences. The Company establishes a valuation allowance for deferred tax assets, when it is determined that it is more likely than not that they will not be realized. Evaluating the need for a valuation allowance on deferred tax assets requires judgment and analysis of all available positive and negative evidence, including recent earnings history and cumulative losses in recent years, reversals of deferred tax liabilities, projected future taxable income, and tax planning strategies to determine whether all or some portion of the deferred tax assets will not be realized. Valuation allowances have been provided primarily against U.S. and state research and development credits and certain acquired net operating losses and deferred tax assets of foreign subsidiaries. Deferred income tax assets and liabilities are measured using enacted tax rates.

The Company utilizes a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained in a dispute with taxing authorities, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount which is more than 50% likely of being realized upon ultimate settlement. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company records interest and penalties related to unrecognized tax benefits in income tax expense.

Government Grants

Government grants are not recognized until there is reasonable assurance that the Company will comply with the conditions attaching to them and that the grants will be received. Any amounts received pursuant to grants are offset against the related operating expenses as the expenses have been incurred.

In 2024, the Company entered into an agreement with the Government of Taiwan pursuant to which the grants contribute up to US$13.3

million to support the development of our advanced PCIe Gen 6 enterprise SSD controller. The government grant is conditional upon meeting the applicable development milestones and is subject to review and approval by the relevant government authorities. The development program is expected to span approximately three years. During the year ended December 31, 2024 and 2025

grants offset against research and development expenses were US$

2,987 thousand and US$728 thousand, respectively.

Foreign Currency Transactions

Foreign currency transactions are recorded at the rates of exchange in effect when the transaction occurs. Gains or losses, resulting from the application of different foreign exchange rates when cash in foreign currency is converted into the entities’ functional currency, or when foreign currency receivables and payables are settled, are credited or charged to income in the period of conversion or settlement. At the balance sheet date, assets and liabilities denominated in foreign currencies are remeasured based on prevailing exchange rates and any resulting gains or losses are credited or charged to income.

Translation of Foreign Currency Financial Statements

The reporting currency of the Company is the U.S. dollars. The functional currency of some of the Company’s subsidiaries is the local currency of the respective entity. Accordingly, the financial statements of the foreign subsidiaries were translated into U.S. dollars at the following exchange rates: assets and liabilities — current rate on the balance sheet date; shareholders’ equity — historical rates; income and expenses — average rate during the period. The resulting translation adjustment is recorded as a separate component of comprehensive income.

Comprehensive Income (Loss)

Comprehensive income (loss) represents net income (loss) plus the results of certain changes in shareholders’ equity during a period from

non-owner

sources. The following table presents the components of accumulated other comprehensive income (loss) as of December 31, 2023, 2024 and 2025:


	Year Ended December 31, 2023									Year Ended December 31, 2024									Year Ended December 31, 2025
	US$									US$									US$
	Foreign currency items			Defined benefit pension plans			Accumulated other comprehensive income (loss)			Foreign currency items			Defined benefit pension plans			Accumulated other comprehensive income (loss)			Foreign currency items		Defined benefit pension plans			Accumulated other comprehensive income (loss)
Beginning balance		3,917			(1,322	)		2,595			2,223			(1,070	)		1,153			1,408		(1,070	)		338
Current-period change		(1,694	)		252			(1,442	)		(815	)		—			(815	)		1,001		—			1,001

Ending balance		2,223			(1,070	)		1,153			1,408			(1,070	)		338			2,409		(1,070	)		1,339

Legal Contingencies

The Company is regularly involved in various claims and legal proceedings. Periodically, the Company reviews the status of each significant matter and assesses the potential financial exposure. Legal costs are expensed as incurred. If the potential loss from any claim or legal proceeding is considered probable and the amount can be estimated, the Company accrues a liability for the estimated loss. Because of uncertainties related to these matters, accruals are based only on the best information available at the time. As additional information becomes available, the Company reassesses the potential liability related to the pending claims and litigation and revises these estimates as appropriate. Such revisions in the estimates of the potential liabilities could have a material impact on the results of operations and financial position. Contingencies that might result in a gain are not recognized until realizable.

Earnings Per Share

Basic earnings per share are computed by dividing net earnings attributable to ordinary shareholders by the weighted-average number of ordinary shares outstanding during the period. Diluted earnings per share are computed by dividing net income attributable to ordinary shareholders by the weighted-average number of ordinary shares and potentially dilutive shares of ordinary shares outstanding during the period. Dilutive shares outstanding include unvested restricted stock units (“RSUs”). Dilutive securities are excluded from the computation of the diluted income per share in periods when their effect is anti-dilutive. The effect of dilutive securities of restricted stock units were 466 thousand shares (117 thousand ADSs), 318 thousand shares (80 thousand ADSs) and 406 thousand shares (101 thousand ADSs) for the years ended December 31, 2023, 2024 and 2025, respectively.

Stock-Based Compensation

The Company accounts for stock-based compensation in accordance with the Accounting Standards Codification (“ASC”) 718,

Compensation — Stock Compensation

. The value of our restricted stock units is based on the fair value of our shares on the date of grant and expensed over the vesting period.

The fair value of RSUs is measured based on the grant date share price, less the present value of expected dividends during the vesting period, discounted at a risk-free interest rate.

Treasury Stock

Treasury stock is stated at cost and shown as a reduction to shareholders’ equity.

The Company retires ordinary shares repurchased. Accordingly, upon retirement the excess of the purchase price over par value is allocated between additional

paid-in

capital and retained earnings based on the average issuance price of the shares repurchased. A repurchase of ADSs is recorded as treasury stock until the Company completes the withdrawal of the underlying ordinary shares from the ADS program.

Recent Accounting Pronouncements

Accounting Pronouncements Recently Adopted

In December 2023, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures

(“ASU

2023-09”).

Under

ASU 2023-09,

entities are required to uniformly classify and present greater disaggregation of information in the rate reconciliation and income taxes paid. ASU

2023-09

is intended to benefit investors by improving the transparency and decision usefulness of income tax disclosures. The new standard is effective for annual periods beginning after December 15, 2024. The Company adopted ASU

2023-09

effective January 1, 2025. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements and related disclosures.

Accounting Pronouncements Not Yet Effective

In October 2023, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative

, to amend certain disclosure and presentation requirements for a variety of topics within the ASC. These amendments align the requirements in the ASC to the removal of certain disclosure requirements set out in Regulation

S-X

and Regulation

S-K,

announced by the SEC. The effective date for each amended topic in the ASC is either the date on which the SEC’s removal of the related disclosure requirement from Regulation

S-X

or Regulation

S-K

becomes effective, or on June 30, 2027, if the SEC has not removed the requirements by that date. Early adoption is prohibited. The adoption of this amendment is not expected to have a material impact on the Company’s financial position, results of operations, cash flows or financial statement disclosures.

In November 2024, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU

2024-03,

Income Statement — Reporting Comprehensive Income — Expense Disaggregation Disclosures (Subtopic

220-40):

Disaggregation of Income Statement Expenses

, which requires disaggregated disclosure of income statement expenses for public business entities. The ASU does not change or remove existing expense disclosure requirements. The ASU also does not change the expense captions an entity presents on the face of the income statement; rather, it requires disaggregation of certain expense captions into specified categories in disclosures within the footnotes to the financial statements. In January 2025, the FASB issued

ASU 2025-01, Income Statement — Reporting Comprehensive Income — Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date

, to clarify the effective date of ASU

2024-03.

This guidance is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the provisions of the amendments and the effect on its future consolidated financial statements.

In July 2025, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU

2025-05,

Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets

. In developing reasonable and supportable forecasts as part of estimating expected credit losses, all entities may elect a practical expedient that assumes that current conditions as of the balance sheet date do not change for the remaining life of the asset. The amendments in this ASU should be applied prospectively. The amendments will be effective for fiscal years beginning after December 15, 2025, and interim periods within those fiscal periods. Early adoption is permitted. The adoption of this amendment is not expected to have a material impact on the Company’s financial position, results of operations, cash flows or financial statement disclosures.

In December 2025, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU 2025-10, Government Grants (Topic 832): Accounting for Government Grants Received by Business Entities

, which adds guidance to ASC 832 on the recognition, measurement, and presentation of government grants. The amendments are effective for fiscal years beginning after December 15, 2028, and interim periods within those fiscal periods. Early adoption is permitted. The adoption of this amendment is not expected to have a material impact on the Company’s financial position, results of operations, cash flows or financial statement disclosures.

In December 2025, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

Interim Reporting (Topic 270): Narrow-Scope Improvements

, which is intended to improve the navigability of the guidance in ASC 270 and clarify when it applies. Under the amendments, an entity is subject to ASC 270 if it provides interim financial statements and notes in accordance with GAAP. The ASU also addresses the form and content of such financial statements, adds lists to ASC 270 of the interim disclosures required by all other Codification topics, and establishes a principle under which an entity must disclose events since the end of the last annual reporting period that have a material impact on the entity. The amendments are not intended to change the fundamental nature of interim reporting or expand or reduce current interim disclosure requirements. The amendments are effective for interim reporting periods within fiscal years beginning after December 15, 2027. Early adoption is permitted and can be applied either (1) prospectively or (2) retrospectively to any or all prior periods presented in the financial statements. The Company is currently evaluating the impact that the adoption will have on its results of operations, financial position, cash flows and financial statement disclosures.

In December 2025, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU 2025-12

Codification Improvements

, as part of the standing project on its agenda to make improvements to the Codification in response to feedback from stakeholders. The amendments make Codification updates to a broad range of Topics arising from technical corrections, unintended application of the Codification, clarifications, and other minor improvements. The amendments in this ASU are effective for fiscal years beginning after December 15, 2026, and interim reporting periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact that the adoption will have on its results of operations, financial position, cash flows and financial statement disclosures.

Long-Term Investments

12 Months Ended

Dec. 31, 2025

Investments, Debt and Equity Securities [Abstract]

Long-Term Investments

6. LONG-TERM INVESTMENTS

As of December 31, 2024 and 2025, the Company held equity investments in several privately-held and listed companies with the carrying value as follows:


	Percentage of Ownership						December 31
	2024			2025			2024		2025
							US$		US$
Non-marketable equity securities:
Cashido Corp. (Cashido)		0	%		0	%		—		—
Vastview Technology, Corp. (Vastview)		0	%		0	%		—		—
Kinara, Inc (Kinara)		12	%		0	%		6,500		—

								6,500		—
Marketable equity securities:
BIWIN Storage Technology Corp. (BIWIN)		0	%		0	%		6,034		11,432
Shenzhen Techwinsemi Technology Corp (TWSC)		0	%		0	%		4,792		18,244

								17,326		29,676

In June 2018, the Company invested US$

3,000

thousand in the preferred stock of Kinara which is accounted for under the cost method. Kinara, previously known as Deep Vision, is a developer of

low-power

deep-learning processors. In March 2020 and May 2021, the Company invested US$

2,000

thousand and US$

1,500

thousand, respectively, in the preferred stock of Kinara. In November 2025, the Company disposed all of Kinara and recognized a disposal gain of US$

21,076

thousand.

In July 2021, the Company invested US$

2,041

thousand in the common stock of BIWIN, which is a leading module maker in China focusing on solid state storage devices. BIWIN is one of our customers and was listed on the Science and Technology Innovation Board of Shanghai Stock Exchange in December 2022. In the fourth quarter of 2024, the Company disposed of common stock of BIWIN with a carry value of US$4,374 thousand and recognized a disposal gain of US$58 thousand. For the years ended December 31, 2023, 2024 and 2025, the Company recorded an unrealized holding gain of US$

8,002

thousand,

unrealized holding loss US$

thousand, and

unrealized holding gain US$

5,204

thousand, respectively, related to BIWIN.

In December 2024, the Company invested US$4,173 thousand in the common stock of TWSC, which is a leading module maker in China focusing on solid state storage devices and is one of our customers and was listed on the Science and Technology Innovation Board of Shenzhen Stock Exchange in 2022. The Company had unrealized holding gains of US$619 thousand and US$13,196 thousand for the year ended December 31, 2024 and 2025, respectively.

Long-lived Assets (Property And Equipment, net) by Geographic Area (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 218,966	$ 188,398	$ 167,417
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	208,415	177,335	155,334
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	10,006	10,369	11,118
Others
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 545	$ 694	$ 965

Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Payables and Accruals [Abstract]
Wages and bonus	$ 65,718	$ 45,478
Dividends	51,298	51,365
License fees and royalties	12,801	9,739
Research and development payable	14,996	10,733
Fixture	3,558	1,450
Lease liabilities – current portion	2,586	2,528
Equipment	4,218	2,308
Professional fees	6,484	11,316
Contract liabilities	82,117	5,032
Construction payment due	6,610	2,373
Others	25,954	20,334
Accrued expenses and other current liabilities	$ 276,340	$ 162,656

Inventories - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Inventory written down	$ 1,360	$ 6,120	$ 7,920

Property and Equipment

12 Months Ended

Dec. 31, 2025

Property, Plant and Equipment [Abstract]

Property and Equipment

7. PROPERTY AND EQUIPMENT


	December 31
	2024		2025
	US$		US$
Cost:
Land		67,640		67,640
Buildings		28,507		95,481
Machinery and equipment		75,326		85,851
Furniture and fixtures		9,506		12,707
Leasehold and buildings improvement		9,590		33,707
Software		69,854		82,403

Total		260,423		377,789

Accumulated depreciation:
Buildings		7,172		8,347
Machinery and equipment		51,791		61,433
Furniture and fixtures		7,148		6,635
Leasehold and buildings improvement		6,488		6,226
Software		62,680		76,943

		135,279		159,584
Prepayment and construction in progress		63,254		761

		188,398		218,966

In October 2023, the Company disposed of its office building in Taipei, Taiwan, recognizing a gain of US$594 thousand for the year ended December 31, 2023.

As of December 31, 2024 and 2025, the Company’s Shanghai office building had net carrying values of US$8,655 thousand and US$8,636 thousand, respectively, with US$2,354 thousand and US$782 thousand leased out.

In September 2018, the Company acquired land in Hsinchu, Taiwan, for US$58,931 thousand to construct its Taiwan headquarters. Construction of the building commenced in January 2021 and was completed in 2025. Upon completion, the building was capitalized at a total cost of US$67,038 thousand.

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Ordinary Shares, par value	$ 0.01	$ 0.01
Ordinary Shares, Authorized	500,000	500,000
Ordinary Shares, Issued	134,245	134,764
Ordinary Shares, outstanding	134,245	134,764

Inventories (Tables)

12 Months Ended

Dec. 31, 2025

Inventory Disclosure [Abstract]

Components of Inventory

The components of inventories are as follows:


	December 31
	2024		2025
	US$		US$
Finished goods		51,118		71,821
Work in process		59,267		177,661
Raw materials		88,844		172,316

		199,229		421,798

Inventories

12 Months Ended

Dec. 31, 2025

Inventory Disclosure [Abstract]

Inventories

5. INVENTORIES

The components of inventories are as follows:


	December 31
	2024		2025
	US$		US$
Finished goods		51,118		71,821
Work in process		59,267		177,661
Raw materials		88,844		172,316

		199,229		421,798

The Company wrote down US$7,920 thousand and US$6,120 thousand and US$1,360 thousand in 2023, 2024 and 2025, respectively, for obsolete or unmarketable inventory.

Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2025

Federal Home Loan Banks [Abstract]

Cash Dividends Declared Per Ordinary Share

The Company’s quarterly dividends are as follows:


	2023				2024				2025
	Dividends Per Share (US$)		Amount (in US$ thousand)		Dividends Per Share (US$)		Amount (in US$ thousand)		Dividends Per Share (US$)		Amount (in US$ thousand)
First quarter	$	—	$	—	$	0.1250	$	16,841	$	0.1250	$	16,988
Second quarter		—		—		0.1250		16,843		0.1250		16,779
Third quarter		—		—		0.1250		16,844		0.1250		16,781
Fourth quarter		0.1250		16,708		0.1250		16,846		0.1250		16,781

			$	16,708			$	67,374			$	67,329

Cash, Cash Equivalents, and Restricted Cash (Tables)

12 Months Ended

Dec. 31, 2025

Cash and Cash Equivalents [Abstract]

Details of Cash, Cash Equivalents, and Restricted Cash


	December 31
	2024		2025
	US$		US$
Cash and deposits in bank		29,386		54,964
Time deposits		246,682		143,375
Repurchase agreements		—		3,503

Total cash and cash equivalents		276,068		201,842
Restricted cash		58,265		75,239

		334,333		277,081

Segment Information (Tables)

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Significant Expenses and Other Expense

The following table presents selected financial information, including significant expenses and other expense information provided to CODM, with respect to the Company’s

single

operating segment for the years ended December 31, 2023, 2024 and 2025:


	2023			2024			2025
	US$			US$			US$
Net sales		639,142			803,552			885,627
Less:
Product costs (1)		364,405			430,784			454,124
Stock-compensation and related payroll expense		142,156			154,831			203,305
Integrated Circuit design related costs		46,429			73,263			72,069
Depreciation and amortization		21,810			25,331			30,174
Income tax expense		8,175			18,160			17,492
Dispute related expenses		6,973			14,385			12,988
Other operating expenses (2)		17,490			14,069			19,930
Interest income		(12,246	)		(14,528	)		(9,663	)
Other segment items (3)		(8,923	)		(1,992	)		(37,427	)

Net income		52,873			89,249			122,635

(1)	Product costs primarily include material, labor and other product related costs, excluding the other categories above.

(2)	Other operating expenses primarily include facilities expenses, sales promotion expenses, professional service expenses and other expenses.

(3)	Other segment items primarily include unrealized holding gain on investment, gain from disposal of long-term investment, foreign exchange gain or loss, interest expense and other income, net as reported in our consolidated statements of income.

Long-Lived Assets (Property and Equipment, Net) by Geographic Area

Long-lived assets (property and equipment, net) by geographic area are as follows:


	Year Ended December 31
	2023		2024		2025
	US$		US$		US$
Taiwan		155,334		177,335		208,415
China		11,118		10,369		10,006
Others		965		694		545

		167,417		188,398		218,966

Revenue by Product Category

The Company groups its products into two categories, based on the markets in which they may be used. The following summarizes the Company’s revenue by product category:


	Year Ended December 31
	2023		2024		2025
	US$		US$		US$
Mobile Storage		632,813		796,365		877,195
Others		6,329		7,187		8,432

		639,142		803,552		885,627

Revenue by Geographic Area

Revenue is attributed to a geographic area based on the

bill-to

location and is summarized as follows:


	Year Ended December 31
	2023		2024		2025
	US$		US$		US$
China		229,037		331,664		495,107
Japan		36,431		143,130		123,870
Singapore		127,642		144,595		78,432
Taiwan		74,284		58,114		74,629
Korea		48,633		73,057		22,551
United States		55,504		13,019		7,966
Others		67,611		39,973		83,072

		639,142		803,552		885,627

Major customers representing at least 10% of net sales

Major customers representing at least 10% of net sales are as follows:


	Year Ended December 31
	2023				2024				2025
	US$		%		US$		%		US$		%
PHISEMI		*		*		107,407		13		216,456		24
Kioxia		*		*		119,727		15		105,704		12
AFASTOR		70,046		11		82,678		10		104,248		12
Micron		144,011		22		151,780		19		86,201		10
SK Hynix		75,836		12		*		*		*		*

*	Less than 10%

Lease (Tables)

12 Months Ended

Dec. 31, 2025

Leases [Abstract]

Summary of Future Lease Payments for the Operating Leases Under the Operating Leases

The maturities of the operating lease liabilities as of December 31, 2025, were as follows:


	Operating Lease Obligations
Fiscal Year:
2026	$	2,887
2027		2,308
2028		1,788
2029		1,698
2030		1,698
2031 and thereafter		4,813

Total		15,192
Less imputed interest		1,142

Present value of lease liabilities		14,050
Less operating lease liabilities-current		2,586

Long-term operating lease liabilities	$	11,464

Commitments And Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Oct. 05, 2023	Feb. 18, 2021
Commitments and Contingencies Disclosure [Line Items]
Restructuring and Related Cost, Expected Cost	$ 101,000
Performance bond certificate of deposit			$ 2,504
Breach Of Purchase Contract
Commitments and Contingencies Disclosure [Line Items]
Loss contingency, termination fee receivable		$ 160,000

Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Feb. 06, 2025
Retained Earnings Adjustments [Line Items]
Dividend declared	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0	$ 0	$ 0	$ 0.5	$ 0.5	$ 0.5
2023 Dividend \| October 30, 2023
Retained Earnings Adjustments [Line Items]
Dividend declared															0.5
2024 Dividend \| October 28, 2024
Retained Earnings Adjustments [Line Items]
Dividend declared														0.5
2025 Dividend \| October 27, 2025
Retained Earnings Adjustments [Line Items]
Dividend declared													$ 0.5
American Depositary Shares
Retained Earnings Adjustments [Line Items]
ADSs repurchased during period, shares													426
ADSs repurchased during period, cost													$ 24,312
Average purchase price per ADS													$ 57.04
American Depositary Shares \| Maximum
Retained Earnings Adjustments [Line Items]
Repurchase of shares																$ 50,000
American Depositary Shares \| 2023 Dividend \| October 30, 2023
Retained Earnings Adjustments [Line Items]
Dividend declared															$ 2
American Depositary Shares \| 2024 Dividend \| October 28, 2024
Retained Earnings Adjustments [Line Items]
Dividend declared														$ 2
American Depositary Shares \| 2025 Dividend \| October 27, 2025
Retained Earnings Adjustments [Line Items]
Dividend declared													$ 2

Summary of Stock Option and Restricted Stock Units Activity (Detail) - 2015 Equity Incentive Plan and 2025 Equity Incentive Plan - Employee Stock Options And Restricted Stock Units - shares shares in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for grant at beginning balance	7,800	9,007	9,580
Restricted stock units granted	(1,460)	(1,225)	(624)
Restricted stock units forfeited	24	18	51
Available for grant at ending balance	18,615	7,800	9,007
Authorized-2025 Plan	20,000
Terminated-2015 Plan	(7,749)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Details of Cash, Cash Equivalents, and Restricted Cash (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Cash and deposits in bank	$ 54,964	$ 29,386
Time deposits	143,375	246,682
Repurchase agreements	3,503	0
Total cash and cash equivalents	201,842	276,068
Restricted cash	75,239	58,265
Total cash ,cash equivalents, and restricted cash	$ 277,081	$ 334,333	$ 368,990	$ 287,055

Revenue by Product Category (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
NET SALES	$ 885,627	$ 803,552	$ 639,142
Mobile Storage
Segment Reporting Information [Line Items]
NET SALES	877,195	796,365	632,813
Others
Segment Reporting Information [Line Items]
NET SALES	$ 8,432	$ 7,187	$ 6,329

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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+ Details

Lease - Summary of Future Lease Payments for the Operating Leases Under the Operating Leases (Detail) $ in Thousands	Dec. 31, 2025 USD ($)
Leases [Abstract]
2026	$ 2,887
2027	2,308
2028	1,788
2029	1,698
2030	1,698
2031 and thereafter	4,813
Total	15,192
Less imputed interest	1,142
Present value of lease liabilities	14,050
Less operating lease liabilities-current	2,586
Long-term operating lease liabilities	$ 11,464
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Liabilities, Current
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent

Income Taxes - Summary of Income Before Income Taxes for Domestic and Foreign Entities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Reconciliation Of Income Taxes [Line Items]
Income recorded in Hong Kong	$ 14,208	$ 34,983	$ 23,741
Income before taxes	140,127	107,409	61,048
Cayman
Reconciliation Of Income Taxes [Line Items]
Income from foreign operations	(21,802)	(5,305)	(17,082)
Others
Reconciliation Of Income Taxes [Line Items]
Income from foreign operations	$ 147,721	$ 77,731	$ 54,389

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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+ Details

Equity Incentive Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Jun. 04, 2025	Jun. 03, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax effect for stock-based compensation benefit (expense) for option and restricted stock units exercised	$ (105)	$ 173	$ (178)
Employee Stock Options And Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax effect for stock-based compensation benefit (expense) for option and restricted stock units exercised	$ 3,490	$ 3,073	$ 4,925
2015 Equity Incentive Plan \| Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares authorized					20,000
2025 Equity Incentive Plan \| Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares authorized				20,000
2015 Equity Incentive Plan and 2025 Equity Incentive Plan \| Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion ratio of restricted stock unit to ordinary shares	one-for-one basis
Total unrecognized compensation cost related to non-vested share-based compensation	$ 6,873

Pension Plan	12 Months Ended
Pension Plan	Dec. 31, 2025
Retirement Benefits [Abstract]
Pension Plan	10. PENSION PLAN SMI Taiwan, the Company’s largest operating company, is a Taiwan registered company and subject to Taiwan’s Labor Pension Act (the “New Act”), which became effective on July 1, 2005, and the pension mechanism under the New Act is deemed a defined contribution plan. The employees who were subject to the Labor Standards Law prior to July 1, 2005 (the “Old Act”) could choose to be subject to the pension mechanism under the New Act or continue to be subject to the pension mechanism under the Old Act. For those employees who were subject to the Old Act and still work for the Company after July 1, 2005 and have chosen to be subject to the Old Act, their seniority as of July 1, 2005 remained . The New Act prescribes that the rate of contribution by an employer to employees’ pension accounts per month will not be less than 6% of each employee’s monthly salary. According to the New Act, SMI Taiwan made monthly contributions and recognized pension costs of US$3,369 thousand, US$3,542 thousand and US$4,386 thousand for the years ended December 31, 2023, 2024 and 2025, respectively.

- Definition

The entire disclosure for retirement benefits.

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+ Details

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Tax Credit Carryforward [Line Items]
Corporate income tax rate	16.50%
Change in valuation allowance	$ 3,556	$ 4,680
Accumulated undistributed earnings from a foreign subsidiary	569,000
Deferred tax liability on undistributed foreign earnings	0
Unrecognized tax benefit	35,258	43,584	$ 43,764	$ 37,105
Total amount of interest expense and penalties	465	1,053	$ 1,072
Total amount of accrued interest and penalties	$ 6,332	$ 6,797
Effective Income Tax Rate Reconciliation, Percent	12.50%	16.90%	13.40%
Minimum
Tax Credit Carryforward [Line Items]
Corporate income tax rate	12.00%
Maximum
Tax Credit Carryforward [Line Items]
Corporate income tax rate	21.00%
Foreign Tax Authority \| Internal Revenue Service (IRS) \| Tax Year 2017
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards for income tax purposes	$ 23,605
Foreign Tax Authority \| Internal Revenue Service (IRS) \| Tax Year 2018
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards for income tax purposes	$ 27,848
Operating loss carryforward expiration year description	carryforward indefinitely
Foreign Tax Authority \| Maximum \| Internal Revenue Service (IRS) \| Tax Year 2017
Tax Credit Carryforward [Line Items]
Federal net operating loss carryforwards expiration year	2037
Foreign Tax Authority \| Research And Development \| Internal Revenue Service (IRS)
Tax Credit Carryforward [Line Items]
Deferred tax assets tax credit carryforwards	$ 2,205
Tax credit carryforward expiration year for federal	2045
State and Local Jurisdiction \| Minimum \| Internal Revenue Service (IRS) \| Tax Year 2017
Tax Credit Carryforward [Line Items]
Federal net operating loss carryforwards expiration year	2026
State and Local Jurisdiction \| Research And Development
Tax Credit Carryforward [Line Items]
Deferred tax assets tax credit carryforwards	$ 1,398
Tax credit carryforward expiration year for state	no expiration date in California

Organization and Operations	12 Months Ended
Organization and Operations	Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Operations	1. ORGANIZATION AND OPERATIONS Silicon Motion Technology Corporation (“SMTC”, collectively with its subsidiaries as the “Company”) is the global leader in supplying NAND flash controllers for solid state storage devices. The Company is a world leading supplier of SSD controllers for servers, PCs and other client devices and is a leading merchant supplier of eMMC and UFS embedded storage controllers used in smartphones, IoT devices and other applications. The Company also supplies customized high-performance and specialized industrial and automotive SSD solutions. Our customers include most of the NAND flash vendors, storage device module makers and leading OEMs. For further information on SMTC, visit us at www.siliconmotion.com. Termination of the Merger Agreement with MaxLinear On May 5, 2022, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with MaxLinear, Inc., a Delaware Corporation (“MaxLinear”), and Shark Merger Sub, an exempted company with limited liability incorporated under the law of the Cayman Islands and a wholly owned subsidiary of MaxLinear, pursuant to which the Company agreed to be acquired by MaxLinear, with (a) holders of our ordinary shares to receive $23.385 in cash and 0.097 shares of MaxLinear common stock, par value $0.0001(“MaxLinear Common Stock”) for each share that they hold (other than certain customary excluded shares), and (b) ADS holders to receive $93.54 in cash and 0.388 shares of MaxLinear Common Stock for each ADS that they hold (other than ADSs representing certain customary excluded shares), in each case, with cash in lieu of any fractional shares of MaxLinear Common Stock (collectively, the “Transaction”). On August 31, 2022, shareholders at the Company’s Extraordinary General Meeting of Shareholders approved the Transaction. On July 26, 2023, the Company and MaxLinear received antitrust approval from the State Administration for Market Regulation of the People’s Republic of China (“SAMR Approval”). Shortly after receiving SAMR Approval, the Company received notice from MaxLinear of its purported termination of the Merger Agreement. MaxLinear did not provide any factual basis for its purported termination, and the Company believes its actions constituted a willful and material breach of the Merger Agreement. The Company has filed a claim in the Singapore International Arbitration Centre (the “SIAC”), which is the venue for dispute resolution under the Merger Agreement, and is currently pursuing payment of the termination fee of $160 million, together with further substantial damages, interest and costs. Under the SIAC Arbitration Rules, all matters relating to the proceedings are confidential. See Note 15 for more information on legal matters related to the termination of the Merger Agreement.

Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2025

Receivables [Abstract]

Summary of Accounts Receivable


	December 31
	2024			2025
	US$			US$
Trade accounts receivable		233,749			211,547
Allowance for doubtful accounts		(5	)		(1	)

		233,744			211,546

Changes in Allowances

The changes in the allowances are summarized as follows:


	Year Ended December 31
	2023			2024			2025
	US$			US$			US$
Allowances for doubtful accounts
Balance, beginning of year		569			20			5
Additions (reversals) charged to expense, net		(549	)		(15	)		(4	)

Balance, end of year		20			5			1

Long-term Investment - Additional Information (Detail) - USD ($) $ in Thousands		1 Months Ended					3 Months Ended	12 Months Ended
	Mar. 31, 2020	Nov. 30, 2025	Dec. 31, 2024	Jul. 31, 2021	May 31, 2021	Jun. 30, 2018	Dec. 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Schedule of Equity and Cost Investments [Line Items]
Unrealized holding gain (loss) on investment								$ 18,400	$ 543	$ 8,002
Simple Agreement For Future Equity
Schedule of Equity and Cost Investments [Line Items]
Invested in common stock	$ 2,000				$ 1,500
Kinara
Schedule of Equity and Cost Investments [Line Items]
Invested in common stock						$ 3,000
Realized investment gains (losses)		$ 21,076					$ 58
BIWIN Storage Technology Corp.(BIWIN)
Schedule of Equity and Cost Investments [Line Items]
Invested in common stock				$ 2,041
Unrealized holding gain (loss) on investment								5,204	(76)	$ 8,002
BIWIN Storage Technology Corp.(BIWIN) \| Common Stock
Schedule of Equity and Cost Investments [Line Items]
Proceeds from sale of equity securities, FV-NI							$ 4,374
Shenzhen Techwinsemi Technology Corp (TWSC) \| Common Stock
Schedule of Equity and Cost Investments [Line Items]
Unrealized holding gain (loss) on investment								$ 13,196	$ 619
Payments to acquire investments			$ 4,173

Cash Dividends Declared Per Ordinary Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Dividends [Abstract]
Dividend Per Share	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0	$ 0	$ 0	$ 0.5	$ 0.5	$ 0.5
Amount	$ 16,781	$ 16,781	$ 16,779	$ 16,988	$ 16,846	$ 16,844	$ 16,843	$ 16,841	$ 16,708	$ 0	$ 0	$ 0	$ 67,329	$ 67,374	$ 16,708

Consolidated Statements Of Changes In Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Ordinary Shares	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (accumulated deficit)	Treasury Stock
Beginning Balance at Dec. 31, 2022	$ 732,601	$ 1,322	$ 303,564	$ 2,595	$ 425,120	$ 0
Beginning Balance, shares at Dec. 31, 2022		132,216
Net income	52,873				52,873
Other comprehensive income (loss)	(1,442)			(1,442)
Stock-based compensation expenses	17,547		17,547
Issuance of ordinary shares upon exercise of restricted stock units, shares		1,460
Issuance of ordinary shares upon exercise of restricted stock units	(46)	$ 15	(61)
Dividends declared	(66,837)				(66,837)
Ending Balance at Dec. 31, 2023	734,696	$ 1,337	321,050	1,153	411,156	0
Ending Balance, shares at Dec. 31, 2023		133,676
Net income	89,249				89,249
Other comprehensive income (loss)	(815)			(815)
Stock-based compensation expenses	16,956		16,956
Issuance of ordinary shares upon exercise of restricted stock units, shares		1,088
Issuance of ordinary shares upon exercise of restricted stock units	(20)	$ 11	(31)
Dividends declared	(67,782)				(67,782)
Ending Balance at Dec. 31, 2024	$ 772,284	$ 1,348	337,975	338	432,623	0
Ending Balance, shares at Dec. 31, 2024	134,764	134,764
Net income	$ 122,635				122,635
Other comprehensive income (loss)	1,001			1,001
Stock-based compensation expenses	26,283		26,283
Issuance of ordinary shares upon exercise of restricted stock units, shares		1,186
Issuance of ordinary shares upon exercise of restricted stock units	(21)	$ 11	(32)
Share repurchase	(24,312)					(24,312)
Treasury stock retired (Shares)		(1,705)
Treasury stock retired		$ (17)	(4,299)		(19,996)	24,312
Dividends declared	(67,133)				(67,133)
Ending Balance at Dec. 31, 2025	$ 830,737	$ 1,342	$ 359,927	$ 1,339	$ 468,129	$ 0
Ending Balance, shares at Dec. 31, 2025	134,245	134,245

Cash, Cash Equivalents, and Restricted Cash - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Cash and Cash Equivalents [Abstract]
Restricted assets-current	$ 71,297	$ 54,645
Restricted cash classified as other assets	$ 3,942	$ 3,620

Insider Trading Policies and Procedures	12 Months Ended
Insider Trading Policies and Procedures	Dec. 31, 2025
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Deferred Income Tax Assets (liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Income Tax Disclosure [Abstract]
Stock-based compensation	$ 3,090	$ 1,520
Allowance for sales return	472	1,024
Inventory reserve	1,939	3,122
Foreign currency translation	7	(126)
Property and equipment	(568)	(628)
Investment tax credits	3,603	3,596
Net operating loss carryforwards	24,636	21,607
Others	7,228	6,563
Valuation allowance	(31,356)	(27,800)
Net deferred tax assets	$ 9,051	$ 8,878

Lease - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating Leased Assets [Line Items]
Lease Expense	$ 4,165	$ 4,339	$ 5,261
Operating Lease Payments	2,687	2,569	3,825
Operating lease right of use assets	13,195	14,674
Operating lease liabilities accrued current	2,586
Operating lease liabilitites long term	$ 11,464
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent
Right-of-use asset obtained in exchange for operating lease liability	$ 189	3,198	$ 13,823
Accounting Standards Update 2016-02
Operating Leased Assets [Line Items]
Operating lease right of use assets	$ 13,195	$ 14,674
Operating lease weighted average remaining lease term	6 years 11 months 8 days	7 years 9 months 14 days
Operating lease weighted average discount rate	2.43%	2.49%
Accounting Standards Update 2016-02 \| Other Current Liabilities
Operating Leased Assets [Line Items]
Operating lease liabilities accrued current	$ 2,586	$ 2,528
Accounting Standards Update 2016-02 \| Other Noncurrent Liabilities
Operating Leased Assets [Line Items]
Operating lease liabilitites long term	$ 11,464	$ 12,413
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent

Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Balance, beginning of year	$ 43,584	$ 43,764	$ 37,105
Increases in tax positions taken in current year	6,328	4,376	16,054
Decrease in tax position taken in prior year primarily related to the resolution of tax audit	(14,654)	(4,556)	(9,395)
Balance, end of year	$ 35,258	$ 43,584	$ 43,764

Accrued Expenses and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2025

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities


	December 31
	2024		2025
	US$		US$
Wages and bonus		45,478		65,718
Dividends		51,365		51,298
License fees and royalties		9,739		12,801
Research and development payable		10,733		14,996
Fixture		1,450		3,558
Lease liabilities – current portion		2,528		2,586
Equipment		2,308		4,218
Professional fees		11,316		6,484
Contract liabilities		5,032		82,117
Construction payment due		2,373		6,610
Others		20,334		25,954

		162,656		276,340

Summary of Significant Accounting Policies - Summary of the Company's Assets and Liabilities that are Measured at Fair Value on a Recurring Basis (Detail) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity investments	$ 29,676	$ 10,826
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity investments	29,676	10,826
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity investments	0	0
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity investments	$ 0	$ 0

- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References + Details

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

Use of Estimates

Concentration of Credit Risk and Significant Customers

write-off

Historically, a relatively small number of customers have accounted for a significant portion of our net sales. Sales to three customers in 2023

Fair Value of Financial Instruments

Level 1 — Use unadjusted quoted prices in active markets for identical assets or liabilities.

Level 3 — Use inputs that are generally unobservable and reflect the use of significant management judgments and estimates.


	Fair Value Measurements at December 31, 2025
	Level 1		Level 2		Level 3		Total
Items measured at fair value on a recurring basis:
Assets
Long-term investments:
Marketable equity investments	$	29,676		—		—	$	29,676


	Fair Value Measurements at December 31, 2024
	Level 1		Level 2		Level 3		Total
Items measured at fair value on a recurring basis:
Assets
Long-term investments:
Marketable equity investments	$	10,826		—		—	$	10,826

The carrying value of investments in

non-marketable

equity securities recorded to fair value on a

non-recurring

non-marketable

equity investments had a carrying value of $6,500 thousand and nil, respectively, and are included in long-term investments on the Company’s consolidated balance sheets.

Cash Equivalents

The Company considers all highly liquid instruments acquired with a remaining maturity of

three months

Allowance for Doubtful Accounts

Inventories

Long-term Investments

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation. Significant additions, renewals and betterments are capitalized, while maintenance and repairs are expensed as incurred.

Lease

The Company determines if an arrangement is a lease at inception. Operating lease

right-of-use

Impairment of Long-Lived Assets

Other Assets

Other assets primarily consist of deposits for building construction and office leases.

Restricted Assets

Restricted assets consist of restricted cash and cash set aside as collateral for obtaining foundry capacity and the government grant restricted for research and development purposes.

Other long-term liabilities

Other long-term liabilities primarily consist of deposit

from construction in progress, noncurrent lease liabilities and unrecognized tax benefit.

Revenue Recognition

Revenue from Contracts with Customer (ASC 606),

The Company provides warranty for its products. Warranty returns have been infrequent and relate to defective or

off-specification

Research and Development

Income Taxes

Government Grants

In 2024, the Company entered into an agreement with the Government of Taiwan pursuant to which the grants contribute up to US$13.3

grants offset against research and development expenses were US$

2,987 thousand and US$728 thousand, respectively.

Foreign Currency Transactions

Translation of Foreign Currency Financial Statements

Comprehensive Income (Loss)

Comprehensive income (loss) represents net income (loss) plus the results of certain changes in shareholders’ equity during a period from

non-owner

sources. The following table presents the components of accumulated other comprehensive income (loss) as of December 31, 2023, 2024 and 2025:


	Year Ended December 31, 2023									Year Ended December 31, 2024									Year Ended December 31, 2025
	US$									US$									US$
	Foreign currency items			Defined benefit pension plans			Accumulated other comprehensive income (loss)			Foreign currency items			Defined benefit pension plans			Accumulated other comprehensive income (loss)			Foreign currency items		Defined benefit pension plans			Accumulated other comprehensive income (loss)
Beginning balance		3,917			(1,322	)		2,595			2,223			(1,070	)		1,153			1,408		(1,070	)		338
Current-period change		(1,694	)		252			(1,442	)		(815	)		—			(815	)		1,001		—			1,001

Ending balance		2,223			(1,070	)		1,153			1,408			(1,070	)		338			2,409		(1,070	)		1,339

Legal Contingencies

Earnings Per Share

Stock-Based Compensation

The Company accounts for stock-based compensation in accordance with the Accounting Standards Codification (“ASC”) 718,

Compensation — Stock Compensation

. The value of our restricted stock units is based on the fair value of our shares on the date of grant and expensed over the vesting period.

The fair value of RSUs is measured based on the grant date share price, less the present value of expected dividends during the vesting period, discounted at a risk-free interest rate.

Treasury Stock

Treasury stock is stated at cost and shown as a reduction to shareholders’ equity.

The Company retires ordinary shares repurchased. Accordingly, upon retirement the excess of the purchase price over par value is allocated between additional

paid-in

Recent Accounting Pronouncements

Accounting Pronouncements Recently Adopted

In December 2023, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures

(“ASU

2023-09”).

Under

ASU 2023-09,

entities are required to uniformly classify and present greater disaggregation of information in the rate reconciliation and income taxes paid. ASU

2023-09

effective January 1, 2025. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements and related disclosures.

Accounting Pronouncements Not Yet Effective

In October 2023, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative

S-X

and Regulation

S-K,

announced by the SEC. The effective date for each amended topic in the ASC is either the date on which the SEC’s removal of the related disclosure requirement from Regulation

S-X

or Regulation

S-K

In November 2024, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU

2024-03,

Income Statement — Reporting Comprehensive Income — Expense Disaggregation Disclosures (Subtopic

220-40):

Disaggregation of Income Statement Expenses

ASU 2025-01, Income Statement — Reporting Comprehensive Income — Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date

, to clarify the effective date of ASU

2024-03.

In July 2025, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU

2025-05,

Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets

In December 2025, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU 2025-10, Government Grants (Topic 832): Accounting for Government Grants Received by Business Entities

In December 2025, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

Interim Reporting (Topic 270): Narrow-Scope Improvements

In December 2025, the Financial Accounting Standards Board (FASB) issued an accounting standard update (ASU),

ASU 2025-12

Codification Improvements

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	15. COMMITMENTS AND CONTINGENCIES Office Building Construction On February 18, 2021, the Company won a bid with a third-party to build an office building in Taipei and we entered into a property development agreement in May 2021, pursuant to which it delivered a performance bond secured by a certificate of deposit. The agreement requires completion of construction within three years after obtaining the construction license. The project broke ground in April 2026, and the remaining performance bond of US$2,504 thousand will be released upon completion of construction. The total development cost is estimated at approximately US$ 101 million, and completion of the project is expected by the end of 2029. Litigation On October 5, 2023, the Company filed a claim in the SIAC against MaxLinear for breaching the Merger Agreement. In the arbitration, the Company is seeking payment of the termination fee of US$160 million, together with further substantial damages, interests, and costs. Following hearings were conducted in October 2025 and March 2026, the arbitration proceedings have concluded, and the parties are awaiting the issuance of the final award. If the Company succeeds in its claims, MaxLinear will likely be ordered to pay the Company’s legal fees and the costs of the arbitration. If the Company does not succeed in some or all of its claims and/or in defending the counterclaim, it may be ordered to pay some or all of MaxLinear’s legal fees and the costs of the arbitration. The quantum of the legal fees and costs to be paid by either party will be decided by the tribunal. No assurance can be given that if an award is granted in the Company’s favor, that the award can be collected or that the Company will not be required to take further measures to be able to collect the award. Under the SIAC Arbitration Rules, all matters relating to the proceedings are confidential. On August 31, 2023, the Company ADS holder (the “Plaintiff”) filed a putative class action complaint in the United States District Court for the Southern District of California, captioned Water Island Event-Driven Fund v. MaxLinear, Inc., No. 23-cv-01607 (S.D. Cal.), asserting claims against MaxLinear and two of its officers (the “MaxLinear Defendants”) for alleged violations of (i) Section 10(b) of the Exchange Act and Rule 10b-5 promulgated thereunder and (ii) Section 20(a) of the Exchange Act, in connection with alleged false and misleading statements made by the MaxLinear Defendants between June 6, 2023 and July 26, 2023 concerning MaxLinear’s intent to consummate the Merger Agreement. On August 28, 2024, the court dismissed the complaint against the MaxLinear Defendants without prejudice for lack of standing. On September 18, 2024, the Plaintiff filed an amended complaint against the MaxLinear Defendants, and also added Silicon Motion and two of our officers, Messrs. Kou and Lai (the “Silicon Motion Defendants”), asserting substantially similar claims under the Exchange Act. The complaint seeks compensatory damages, including interest, costs and expenses, and such other equitable or injunctive relief that the court deems appropriate. The Silicon Motion Defendants filed a motion to dismiss the amended complaint on November 25, 2024, as did the MaxLinear Defendants. The U.S. District Court granted the Silicon Motion Defendants’ motion to dismiss all claims asserted against them with prejudice on July 15, 2025. The Plaintiff has appealed the dismissal of their claims to the United States Court of Appeals for the Ninth Circuit on August 8, 2025. The Silicon Motion Defendants believe that the claims asserted against them are without merit and intend to continue to defend themselves vigorously on appeal.

Significant Expenses and Other Expense (Detail) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2025

Dec. 31, 2024

Dec. 31, 2023

Segment Reporting [Abstract]

Net sales

$ 885,627

$ 803,552

$ 639,142

Product costs

^[1]

454,124

430,784

364,405

Stock-compensation and related payroll expense

203,305

154,831

142,156

Integrated Circuit design related costs

72,069

73,263

46,429

Depreciation and amortization

30,174

25,331

21,810

Income tax expense

17,492

18,160

8,175

Dispute related expenses

12,988

14,385

6,973

Other operating expenses

^[2]

19,930

14,069

17,490

Interest income

(9,663)

(14,528)

(12,246)

Other segment items

^[3]

(37,427)

(1,992)

(8,923)

Net Income (Loss)

$ 122,635

$ 89,249

$ 52,873

[1]	Product costs primarily include material, labor and other product related costs, excluding the other categories above.
[2]	Other operating expenses primarily include facilities expenses, sales promotion expenses, professional service expenses and other expenses.
[3]	Other segment items primarily include unrealized holding gain on investment, gain from disposal of long-term investment, foreign exchange gain or loss, interest expense and other income, net as reported in our consolidated statements of income.

Equity Incentive Plan

12 Months Ended

Dec. 31, 2025

Share-based Payment Arrangement [Abstract]

Equity Incentive Plan

13. EQUITY INCENTIVE PLAN

2015 Equity

Incentive

Plan and 2025 Equity

Incentive

Plan

Restricted stock units are converted into the Company’s ordinary shares upon vesting on

one-for-one

basis. The vesting of restricted stock unit is subject to the employee’s continuing service to the Company. The cost of these awards is determined using the fair value of the Company’s ordinary share on the date of the grant, and compensation is recognized on a straight-line basis over the requisite service period. The Company’s restricted stock units are considered

non-vested

share awards as defined under ASC 718.

On June 3, 2015, the Company adopted its 2015 Equity Incentive Plan (“the 2015 Plan”). The 2015 Plan provides for the grant of stock options, stock bonuses, restricted stock awards, restricted stock units and stock appreciation rights, which may be granted to employees (including officers), directors and consultants. The 2015 Plan reserved 20,000 thousand shares of ordinary shares for issuance upon exercise of stock options and restricted stock units.

On June 4, 2025, the Company adopted its 2025 Equity Incentive Plan (“the 2025 Plan”). The 2025 Plan provides for the grant of stock options, stock bonuses, restricted stock awards, restricted stock units and stock appreciation rights, which may be granted to employees (including officers), directors and consultants. The 2025 Plan reserved 20,000 thousand shares of ordinary shares for issuance upon exercise of stock options and restricted stock units.

Restricted Stock Units Activity

The following is a summary of the 2015 Plan and the 2025 Plan, which includes restricted stock units:


	Unit (in Thousands)
Available for grant at January 1, 2023		9,580
Restricted stock units granted		(624	)
Restricted stock units forfeited		51
Available for grant at December 31, 2023		9,007
Restricted stock units granted		(1,225	)
Restricted stock units forfeited		18

Available for grant at December 31, 2024		7,800
Authorized-2025 Plan		20,000
Terminated-2015 Plan		(7,749	)
Restricted stock units granted		(1,460	)
Restricted stock units forfeited		24

Available for grant at December 31, 2025		18,615

The related tax effect for stock-based compensation benefit (expense) were US$(178) thousand, US$173 thousand and US$(105) thousand for 2023, 2024 and 2025, respectively. The related tax benefit from stock-based compensation expense for restricted stock units exercised during 2023, 2024 and 2025 was US$4,925 thousand, US$3,073 thousand and US$3,490 thousand, respectively. The related tax effect was determined using applicable tax rates.

Restricted Stock Units

A summary of the status of restricted stock units and changes is as follows:


	Number of Non-vested Stock Units (in Thousands)			Weighted Average Grant Date Fair Value (US$)		Weight Average Remaining Recognition Period (Years)
Non-vested at January 1, 2023		1,977			17.89		0.66
Restricted stock units granted		624			13.51
Restricted stock units vested		(1,460	)		18.36
Restricted stock units forfeited		(51	)		16.38

Non-vested at December 31, 2023		1,090			15.00		0.13
Restricted stock units granted		1,225			15.68
Restricted stock units vested		(1,089	)		14.94
Restricted stock units forfeited		(18	)		15.26

Non-vested at December 31, 2024		1,208			15.68		0.25
Restricted stock units granted		1,460			19.51
Restricted stock units vested		(1,186	)		15.63
Restricted stock units forfeited		(24	)		19.44

Non-vested at December 31, 2025		1,458			19.46		0.29

As of December 31, 2025, there was US$6,873 thousand of total unrecognized compensation cost related to restricted stock units granted under the 2015 Plan and the 2025 Plan.

Stock-based Compensation Expense

The following table shows total stock-based compensation expense included in the Consolidated Statements of Income for the years ended December 31, 2023, 2024 and 2025.


	Year Ended December 31
	2023		2024		2025
	US$		US$		US$
Cost of sales		406		311		411
Research and development		11,709		11,284		17,874
Sales and marketing		1,858		1,954		3,428
General and administrative		3,574		3,407		4,570

		17,547		16,956		26,283

Summary of Major Jurisdictions and Tax Year Subject to Examination Tax Authorities (Detail)	12 Months Ended
	Dec. 31, 2025
China
Income Tax Examination [Line Items]
Years Subject to Income Tax Examination	2022 and onward
HONG KONG
Income Tax Examination [Line Items]
Years Subject to Income Tax Examination	2022 and onward
Taiwan
Income Tax Examination [Line Items]
Years Subject to Income Tax Examination	2020 and onward
United States
Income Tax Examination [Line Items]
Years Subject to Income Tax Examination	2020 onward

Segment Information

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Segment And Geographic Information

16. SEGMENT AND GEOGRAPHIC INFORMATION

The Company is the global leader and pioneer in developing NAND flash controllers for solid state storage devices. The Company currently operates as one

reportable segment. The Chief Operating Decision Maker (“CODM”) is the Chief Executive Officer, who is directly involved in the Company’s operations and product development. The CODM is ultimately responsible for and actively involved in the allocation of resources and the assessment of the Company’s performance using consolidated net income reported on the consolidated statements of income, supplemented by revenue information disaggregated by geographic region and target customers. The measure of segment assets is reported on the consolidated balance sheet as total assets. The CODM uses consolidated net income to evaluate income generated in determining whether to reinvest profits in

the segment or to deploy such profits for other purposes, such as acquisitions or share repurchases. Net income is also used to monitor budgeted results compared to actual performance. In addition, the CODM uses consolidated net income in competitive analyses by benchmarking the segment’s performance against that of the Company’s competitors. These competitive analyses, together with comparisons of budgeted and actual results, are used in assessing segment performance and in determining management and variable compensation. The Company’s organizational structure is functionally aligned with department heads and shared resources reporting directly to the CODM. The Company employs a highly integrated product development approach, with proprietary technologies utilized across multiple products and substantially all integrated circuits manufactured using similar processes. As a result, the Company operates as a single operating segment.

The following table presents selected financial information, including significant expenses and other expense information provided to CODM, with respect to the Company’s

single

operating segment for the years ended December 31, 2023, 2024 and 2025:


	2023			2024			2025
	US$			US$			US$
Net sales		639,142			803,552			885,627
Less:
Product costs (1)		364,405			430,784			454,124
Stock-compensation and related payroll expense		142,156			154,831			203,305
Integrated Circuit design related costs		46,429			73,263			72,069
Depreciation and amortization		21,810			25,331			30,174
Income tax expense		8,175			18,160			17,492
Dispute related expenses		6,973			14,385			12,988
Other operating expenses (2)		17,490			14,069			19,930
Interest income		(12,246	)		(14,528	)		(9,663	)
Other segment items (3)		(8,923	)		(1,992	)		(37,427	)

Net income		52,873			89,249			122,635

(1)	Product costs primarily include material, labor and other product related costs, excluding the other categories above.

(2)	Other operating expenses primarily include facilities expenses, sales promotion expenses, professional service expenses and other expenses.

(3)	Other segment items primarily include unrealized holding gain on investment, gain from disposal of long-term investment, foreign exchange gain or loss, interest expense and other income, net as reported in our consolidated statements of income.

This expense information reflects management’s internal classification used to assess financial and operational performance and may not align with classifications used by peer companies. As a result, this expense information should not be considered in isolation or as substitute for analysis of the Company’s results in conjunction with the accompanying consolidated financial statements and notes thereto.

Long-lived assets (property and equipment, net) by geographic area are as follows:


	Year Ended December 31
	2023		2024		2025
	US$		US$		US$
Taiwan		155,334		177,335		208,415
China		11,118		10,369		10,006
Others		965		694		545

		167,417		188,398		218,966

The Company groups its products into two categories, based on the markets in which they may be used. The following summarizes the Company’s revenue by product category:


	Year Ended December 31
	2023		2024		2025
	US$		US$		US$
Mobile Storage		632,813		796,365		877,195
Others		6,329		7,187		8,432

		639,142		803,552		885,627

Revenue is attributed to a geographic area based on the

bill-to

location and is summarized as follows:


	Year Ended December 31
	2023		2024		2025
	US$		US$		US$
China		229,037		331,664		495,107
Japan		36,431		143,130		123,870
Singapore		127,642		144,595		78,432
Taiwan		74,284		58,114		74,629
Korea		48,633		73,057		22,551
United States		55,504		13,019		7,966
Others		67,611		39,973		83,072

		639,142		803,552		885,627

Major customers representing at least 10% of net sales are as follows:


	Year Ended December 31
	2023				2024				2025
	US$		%		US$		%		US$		%
PHISEMI		*		*		107,407		13		216,456		24
Kioxia		*		*		119,727		15		105,704		12
AFASTOR		70,046		11		82,678		10		104,248		12
Micron		144,011		22		151,780		19		86,201		10
SK Hynix		75,836		12		*		*		*		*

*	Less than 10%

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482810/280-10-50-34

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-26C

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-26B

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-40

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/280/tableOfContent

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-26

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-41

+ Details

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 122,635	$ 89,249	$ 52,873
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	30,174	25,331	21,810
Loss on modification of lease	0	0	230
Unrealized holding gain on investment	(18,400)	(543)	(8,002)
Stock-based compensation	26,283	16,956	17,547
Gain from disposal of long-term investment	(21,076)	(58)	0
Loss (gain) on disposal of property and equipment	108	7	(215)
Deferred income taxes	(173)	(422)	428
Changes in operating assets and liabilities:
Accounts receivable	22,198	(39,043)	11,404
Inventories	(215,175)	4,870	72,127
Prepaid expenses and other current assets	(13,091)	(1,842)	(6,563)
Other assets	(20)	(951)	(7)
Notes and accounts payable	16,972	(37,813)	19,563
Refund liabilities	44	2,639	(3,142)
Accrued expenses and other current liabilities	107,871	12,798	(1,634)
Lease liabilities	588	(638)	712
Income tax payable	9,319	5,563	(34,570)
Other liabilities	(6,897)	992	6,522
Net cash provided by operating activities	61,360	77,095	149,083
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of long-term investments	0	(4,173)	0
Proceeds from disposal of long-term investments	27,575	4,432	0
Purchase of property and equipment	(55,065)	(44,351)	(50,313)
Proceeds from disposal of properties	87	3	1,228
Net cash used in investing activities	(27,403)	(44,089)	(49,085)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid	(67,200)	(67,255)	(16,690)
Share repurchase	(24,312)	0	0
Net cash used in financing activities	(91,512)	(67,255)	(16,690)
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	(57,555)	(34,249)	83,308
EFFECT OF EXCHANGE RATE CHANGES	303	(408)	(1,373)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, BEGINNING OF YEAR	334,333	368,990	287,055
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, END OF YEAR	277,081	334,333	368,990
SUPPLEMENTAL INFORMATION
Income taxes paid	16,713	10,111	36,316
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid purchase of property and equipment included in accounts payable and accrued liabilities	10,827	4,681	4,301
Dividend declared included in accrued expenses and accrued liabilities	$ 50,470	$ 50,665	$ 50,147

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 122,635	$ 89,249	$ 52,873

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Summary of Significant Accounting Policies - Additional Information (Detail) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($) Customer shares	Dec. 31, 2024 USD ($) Customer shares	Dec. 31, 2023 USD ($) Customer shares
Significant Accounting Policies [Line Items]
Subsidiary ownership percentage	100.00%
Number of customers accounted for 10% or more sales \| Customer	4	4	3
Depreciation and amortization of property & equipment	$ 30,174	$ 25,331	$ 21,810
Evaluation of tax benefits realized upon settlement	50.00%
Long-term investments	$ 0	6,500
Government assistance, award amount		13,300
Government contract receivable	$ 728	$ 2,987
Minimum
Significant Accounting Policies [Line Items]
Short term investment maturity period	3 months
Maximum
Significant Accounting Policies [Line Items]
Short term investment maturity period	1 year
Net sales \| Customers accounted for 10% or more \| Top Ten Customers
Significant Accounting Policies [Line Items]
Major customers percentage of net sales	82.00%	84.00%	75.00%
Net sales \| Customers accounted for 10% or more \| Two Customers
Significant Accounting Policies [Line Items]
Major customers percentage of net sales			45.00%
Net sales \| Customers accounted for 10% or more \| Three Customers
Significant Accounting Policies [Line Items]
Major customers percentage of net sales		57.00%
Net sales \| Customers accounted for 10% or more \| Four Customer
Significant Accounting Policies [Line Items]
Major customers percentage of net sales	58.00%
Employee Stock Option And Restricted Stock Units
Significant Accounting Policies [Line Items]
The effect of dilutive securities of employee stock options and restricted stock units \| shares	406	318	466
Employee Stock Option And Restricted Stock Units \| American Depositary Shares
Significant Accounting Policies [Line Items]
The effect of dilutive securities of employee stock options and restricted stock units \| shares	101	80	117
Software \| Minimum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	1 year
Software \| Maximum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	5 years
Buildings \| Minimum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	25 years
Buildings \| Maximum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	50 years
Machinery and Equipment \| Minimum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	2 years
Machinery and Equipment \| Maximum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	6 years
Furniture and Fixtures \| Minimum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	3 years
Furniture and Fixtures \| Maximum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	8 years
Leasehold And Building Improvement \| Minimum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	2 years
Leasehold And Building Improvement \| Maximum
Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful life	6 years

Components of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Inventory Disclosure [Abstract]
Finished goods	$ 71,821	$ 51,118
Work in process	177,661	59,267
Raw materials	172,316	88,844
Inventory, Net	$ 421,798	$ 199,229

Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
NET SALES	$ 885,627	$ 803,552	$ 639,142
COST OF SALES	458,118	434,787	368,752
GROSS PROFIT	427,509	368,765	270,390
OPERATING EXPENSES
Research and development	262,718	217,822	174,357
Sales and marketing	34,383	27,450	26,920
General and administrative	37,371	31,354	27,923
Loss from settlement of litigation	0	1,250	1,312
Total operating expenses	334,472	277,876	230,512
OPERATING INCOME	93,037	90,889	39,878
NON-OPERATING INCOME (EXPENSES)
Unrealized holding gain on investment	18,400	543	8,002
Gain from disposal of long-term investment	21,076	58	0
Interest income	9,663	14,528	12,246
Foreign exchange gain (loss), net	(2,067)	1,391	914
Other income	18	0	8
Total non-operating income (expenses)	47,090	16,520	21,170
INCOME BEFORE INCOME TAX	140,127	107,409	61,048
INCOME TAX EXPENSE	17,492	18,160	8,175
NET INCOME	$ 122,635	$ 89,249	$ 52,873
EARNINGS PER ORDINARY SHARE:
Basic	$ 0.91	$ 0.66	$ 0.4
Diluted	$ 0.91	$ 0.66	$ 0.4
WEIGHTED AVERAGE ORDINARY SHARES OUTSTANDING
Basic (Thousands)	134,312	134,570	133,413
Diluted (Thousands)	134,718	134,888	133,879
EARNINGS PER ADS (one ADS equals four ordinary shares):
Basic	$ 3.65	$ 2.65	$ 1.59
Diluted	$ 3.64	$ 2.65	$ 1.58
WEIGHTED AVERAGE ADS OUTSTANDING
Basic (Thousands)	33,578	33,642	33,353
Diluted (Thousands)	33,679	33,722	33,470

Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended												12 Months Ended
	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Stockholders' Equity [Abstract]
Dividends declared, per share	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0	$ 0	$ 0	$ 0.5	$ 0.5	$ 0.5

Long-Term Investments (Tables)

12 Months Ended

Dec. 31, 2025

Investments, Debt and Equity Securities [Abstract]

Long-Term Investments

As of December 31, 2024 and 2025, the Company held equity investments in several privately-held and listed companies with the carrying value as follows:


	Percentage of Ownership						December 31
	2024			2025			2024		2025
							US$		US$
Non-marketable equity securities:
Cashido Corp. (Cashido)		0	%		0	%		—		—
Vastview Technology, Corp. (Vastview)		0	%		0	%		—		—
Kinara, Inc (Kinara)		12	%		0	%		6,500		—

								6,500		—
Marketable equity securities:
BIWIN Storage Technology Corp. (BIWIN)		0	%		0	%		6,034		11,432
Shenzhen Techwinsemi Technology Corp (TWSC)		0	%		0	%		4,792		18,244

								17,326		29,676

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
Cybersecurity Risk Management and Strategy Disclosure	Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	Risk Management and Strategy Cybersecurity risk management is an integral part of our overall enterprise risk management program. Our cybersecurity risk management program is designed based on the National Institute of Standards and Technology (NIST) cybersecurity framework. This framework includes steps for (a) identifying cybersecurity threats, assessing the severity, identifying the source and whether the threat is associated with a third-party service provider; (b) reporting material cybersecurity incidents to management and our board of directors; (c) implementing safeguards, countermeasures and mitigation strategies; and (d) remediation and restoration of the affected systems. Our cybersecurity team also engages third-party security experts for defense protection capability assessment and system enhancements. We also maintain a third-party risk management process under which we assess the cybersecurity practices of key third-party service providers prior to engagement and on a periodic basis thereafter, including through contractual requirements, security questionnaires, and, where appropriate, third-party security assessments. We require key third-party service providers that have access to our systems or data to implement and maintain appropriate cybersecurity controls and to notify us promptly of any cybersecurity incident that may affect our systems or data. In addition, our cybersecurity team provides trainings, security exercises, security awareness electronic direct mail (eDM) and social engineering drills regularly. Our dedicated information technology (“IT”) personnel are experienced information systems security professionals and information security managers with more than 20 years of relevant experience. Our IT team provides cybersecurity reports quarterly that cover, among other topics, suspicious behaviors, end devices security logs analysis, suspicious activity analysis and statistics, and updates to the Company’s cybersecurity programs and mitigation strategies. In 2025, we did not identify any cybersecurity threats that have materially affected or are reasonably likely to materially affect our business strategy, results of operations, or financial condition. However, despite our efforts, we cannot eliminate all risks from cybersecurity threats, or provide assurances that we have not experienced an undetected cybersecurity incident.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	Cybersecurity risk management is an integral part of our overall enterprise risk management program.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Text Block]	In 2025, we did not identify any cybersecurity threats that have materially affected or are reasonably likely to materially affect our business strategy, results of operations, or financial condition. However, despite our efforts, we cannot eliminate all risks from cybersecurity threats, or provide assurances that we have not experienced an undetected cybersecurity incident.
Cybersecurity Risk Board of Directors Oversight [Text Block]	Corporate Governance Our board of directors has overall oversight responsibility for our risk management, and delegates cybersecurity risk management oversight to the audit committee. The audit committee is responsible for ensuring that management has processes in place designed to identify and evaluate cybersecurity risks to which the company is exposed and implement processes and programs to manage cybersecurity risks and mitigate cybersecurity incidents. The audit committee receives cybersecurity risk updates from management at least quarterly, including the quarterly cybersecurity reports prepared by our IT team, and discusses cybersecurity risk management as a standing item at its regular meetings. The audit committee reports to the full board of directors on cybersecurity matters as appropriate. At the management level, responsibility for assessing and managing cybersecurity risks is led by our IT head / Chief Information Officer (“CIO”), together with a dedicated cybersecurity team. This cybersecurity team includes a management-level incident response and notification committee (the “Incident Notification Committee”), which is responsible for the escalation, evaluation, and reporting of significant cybersecurity incidents to senior management and the audit committee. In addition to incident-specific reporting, the IT head / CIO provides routine cybersecurity risk updates to senior management and the audit committee on at least a quarterly basis, covering the Company’s overall cybersecurity posture, emerging threats, risk mitigation activities, and the status of cybersecurity programs and controls. Our cybersecurity operations are supported by the dedicated cybersecurity team, including personnel responsible for cybersecurity monitoring, threat detection, incident response, and remediation. This team reports to the IT head / CIO and provides regular updates to the Incident Notification Committee and senior management. In addition, we engage external cybersecurity consultants and specialists, as needed, to support risk assessments, penetration testing, and incident investigations. Management is responsible for identifying, considering, and assessing material cybersecurity risks on an ongoing basis, and for establishing and maintaining processes designed to ensure that such risks are appropriately monitored and mitigated. These processes include continuous network monitoring, vulnerability assessments, incident response planning, and implementation of cybersecurity controls and technologies. With respect to relevant expertise, our IT head / CIO has extensive experience in information technology management, including oversight of cybersecurity programs in various industries. In addition, members of our cybersecurity team possess relevant technical expertise in areas such as network security, system architecture, threat intelligence, and incident response, and may hold industry-recognized Certified Information Systems Security Professional (CISSP) and Systems Security Certified Practitioner (SSCP), Certified Ethical Hacker (CEH) and ISO27001 certifications.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	Our board of directors has overall oversight responsibility for our risk management, and delegates cybersecurity risk management oversight to the audit committee. The audit committee is responsible for ensuring that management has processes in place designed to identify and evaluate cybersecurity risks to which the company is exposed and implement processes and programs to manage cybersecurity risks and mitigate cybersecurity incidents. The audit committee receives cybersecurity risk updates from management at least quarterly, including the quarterly cybersecurity reports prepared by our IT team, and discusses cybersecurity risk management as a standing item at its regular meetings. The audit committee reports to the full board of directors on cybersecurity matters as appropriate.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Our cybersecurity team also engages third-party security experts for defense protection capability assessment and system enhancements. We also maintain a third-party risk management process under which we assess the cybersecurity practices of key third-party service providers prior to engagement and on a periodic basis thereafter, including through contractual requirements, security questionnaires, and, where appropriate, third-party security assessments. We require key third-party service providers that have access to our systems or data to implement and maintain appropriate cybersecurity controls and to notify us promptly of any cybersecurity incident that may affect our systems or data. In addition, our cybersecurity team provides trainings, security exercises, security awareness electronic direct mail (eDM) and social engineering drills regularly.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Our dedicated information technology (“IT”) personnel are experienced information systems security professionals and information security managers with more than 20 years of relevant experience. Our IT team provides cybersecurity reports quarterly that cover, among other topics, suspicious behaviors, end devices security logs analysis, suspicious activity analysis and statistics, and updates to the Company’s cybersecurity programs and mitigation strategies.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Refund Liabilities - Summary of Change in Refund Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Other Liabilities [Abstract]
Balance, beginning of year	$ 5,968	$ 3,329
Additions	1,838	5,209
Actual sales return and discount	(1,794)	(2,570)
Balance, end of year	$ 6,012	$ 5,968

Organization and Operations - Additional Information (Detail) - USD ($)			12 Months Ended
	Jul. 26, 2023	May 05, 2022	Dec. 31, 2025	Dec. 31, 2024
Organization and Operations [Line Items]
Common stock, par or stated value per share			$ 0.01	$ 0.01
Merger Agreement \| Maxlinear Inc
Organization and Operations [Line Items]
Payment for termination fee	$ 160,000,000
Merger Agreement \| Maxlinear Inc \| American Depositary Shares
Organization and Operations [Line Items]
Payments to Acquire Businesses, Gross			$ 93.54
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares			0.388
Merger Agreement \| Maxlinear Inc \| Common Stock
Organization and Operations [Line Items]
Payments to Acquire Businesses, Gross		$ 23.385
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares		0.097
Common stock, par or stated value per share		$ 0.0001

Summary of Status of Restricted Stock Units and Changes (Detail) - Restricted Stock Units - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Number of Nonvested Stock Units
Nonvested at beginning period	1,208	1,090	1,977
Restricted stock units granted	1,460	1,225	624
Restricted stock units vested	(1,186)	(1,089)	(1,460)
Restricted stock units forfeited	(24)	(18)	(51)
Nonvested at ending period	1,458	1,208	1,090	1,977
Weighted Average Grant Date Fair Value
Nonvested at beginning period	$ 15.68	$ 15	$ 17.89
Restricted stock units granted	19.51	15.68	13.51
Restricted stock units vested	15.63	14.94	18.36
Restricted stock units forfeited	19.44	15.26	16.38
Nonvested at ending period	$ 19.46	$ 15.68	$ 15	$ 17.89
Weighted Average Remaining Recognition Period (Years)
Nonvested at ending period	3 months 14 days	3 months	1 month 17 days	7 months 28 days

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Summary of the Company's Assets and Liabilities that are Measured at Fair Value on a Recurring Basis


	Fair Value Measurements at December 31, 2025
	Level 1		Level 2		Level 3		Total
Items measured at fair value on a recurring basis:
Assets
Long-term investments:
Marketable equity investments	$	29,676		—		—	$	29,676


	Fair Value Measurements at December 31, 2024
	Level 1		Level 2		Level 3		Total
Items measured at fair value on a recurring basis:
Assets
Long-term investments:
Marketable equity investments	$	10,826		—		—	$	10,826

Components of Accumulated Other Comprehensive Income (Loss)

The following table presents the components of accumulated other comprehensive income (loss) as of December 31, 2023, 2024 and 2025:


	Year Ended December 31, 2023									Year Ended December 31, 2024									Year Ended December 31, 2025
	US$									US$									US$
	Foreign currency items			Defined benefit pension plans			Accumulated other comprehensive income (loss)			Foreign currency items			Defined benefit pension plans			Accumulated other comprehensive income (loss)			Foreign currency items		Defined benefit pension plans			Accumulated other comprehensive income (loss)
Beginning balance		3,917			(1,322	)		2,595			2,223			(1,070	)		1,153			1,408		(1,070	)		338
Current-period change		(1,694	)		252			(1,442	)		(815	)		—			(815	)		1,001		—			1,001

Ending balance		2,223			(1,070	)		1,153			1,408			(1,070	)		338			2,409		(1,070	)		1,339

Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Assets and Liabilities Eliminated upon Consolidation [Abstract]
Beginning balance, Foreign currency items	$ 1,408	$ 2,223	$ 3,917
Current-period change, Foreign currency items	1,001	(815)	(1,694)
Ending balance, Foreign currency items	2,409	1,408	2,223
Beginning balance, Defined benefit pension plans	(1,070)	(1,070)	(1,322)
Current-period change, Defined benefit pension plans	0	0	252
Ending balance, Defined benefit pension plans	(1,070)	(1,070)	(1,070)
Beginning balance, Accumulated other comprehensive income (loss)	338	1,153	2,595
Current-period change, Accumulated other comprehensive income (loss)	1,001	(815)	(1,442)
Ending balance, Accumulated other comprehensive income (loss)	$ 1,339	$ 338	$ 1,153

- Definition

Amount, after tax, of accumulated increase (decrease) in equity from transaction and other event and circumstance from nonowner source.

+ References + Details

- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

+ References

+ Details

Accrued Expenses and Other Current Liabilities

12 Months Ended

Dec. 31, 2025

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

9. ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES


	December 31
	2024		2025
	US$		US$
Wages and bonus		45,478		65,718
Dividends		51,365		51,298
License fees and royalties		9,739		12,801
Research and development payable		10,733		14,996
Fixture		1,450		3,558
Lease liabilities – current portion		2,528		2,586
Equipment		2,308		4,218
Professional fees		11,316		6,484
Contract liabilities		5,032		82,117
Construction payment due		2,373		6,610
Others		20,334		25,954

		162,656		276,340

Contract liabilities are comprised of deferred revenue and reflect the Company’s obligation to transfer goods or services primarily to a customer for which the Company has received consideration. The amount of revenue recognized during the year ended December 31, 2025, that was included in deferred revenue balance at December 31, 2024 was not material.

As of the end of the reporting period, certain performance obligations associated with contracts remain unsatisfied or only partially satisfied. The Company has elected the practical expedient and does not disclose the value of unsatisfied performance obligations for contracts with an original expected duration of one year or less.

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Current Assets
Cash and cash equivalents	$ 201,842	$ 276,068
Accounts receivable, net	211,546	233,744
Inventories	421,798	199,229
Restricted assets-current	71,297	54,645
Prepaid expenses and other current assets	36,885	31,187
Total current assets	943,368	794,873
Long-term investments	29,676	17,326
Property and equipment, net	218,966	188,398
Deferred income tax assets, net	9,051	8,878
Operating lease assets	13,195	14,674
Other assets	8,463	7,187
Total assets	1,222,719	1,031,336
Current Liabilities
Notes and accounts payable	34,745	17,773
Income tax payable	22,426	13,107
Refund liabilities	6,012	5,968
Accrued expenses and other current liabilities	276,340	162,656
Total current liabilities	339,523	199,504
Other long-term liabilities	52,459	59,548
Total liabilities	391,982	259,052
Commitments and Contingencies (Note 15)
Shareholders' Equity
Ordinary Shares at US$0.01 par value per share Authorized: 500,000 thousand shares Issued and outstanding: 134,764 thousand shares in 2024 and 134,245 thousand shares in 2025	1,342	1,348
Additional paid-in capital	359,927	337,975
Accumulated other comprehensive income	1,339	338
Retained earnings	468,129	432,623
Total shareholders' equity	830,737	772,284
Total liabilities and shareholders' equity	$ 1,222,719	$ 1,031,336

Summary of Accounts Receivable (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Receivables [Abstract]
Trade accounts receivable	$ 211,547	$ 233,749
Allowance for doubtful accounts	(1)	(5)	$ (20)	$ (569)
Accounts receivable, net	$ 211,546	$ 233,744

Refund Liabilities

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Refund Liabilities

8. REFUND LIABILITIES

Estimated sales returns and other allowances are made and adjusted based on historical experience and the consideration of varying contractual terms.

The changes in the refund liabilities are summarized as follows:


	Year Ended December 31
	2024			2025
	US$			US$
Refund liabilities
Balance, beginning of year		3,329			5,968
Additions		5,209			1,838
Actual sales return and discount		(2,570	)		(1,794	)

Balance, end of year		5,968			6,012

Income Taxes - Schedule Of Income Tax Paid By Individual Jurisdiction (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($)
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income Tax Paid, Federal, after Refund Received	$ 5,729
Total income tax paid, net of refunds	16,713
Macau
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income Tax Paid, Foreign, after Refund Received	10,078
Others
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income Tax Paid, Foreign, after Refund Received	$ 906

Cover Page	12 Months Ended
Cover Page	Dec. 31, 2025 shares
Document Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2025
Document Fiscal Year Focus	2025
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Entity Registrant Name	Silicon Motion Technology Corporation
Entity Filer Category	Large Accelerated Filer
Entity File Number	000-51380
Entity Well-known Seasoned Issuer	Yes
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Document Registration Statement	false
Document Accounting Standard	U.S. GAAP
Entity Shell Company	false
Entity Voluntary Filers	No
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Address, Address Line One	Flat C, 19/F, Wing Cheong Commercial Building
Entity Address, Address Line Two	Nos 19-25 Jervois Street
Entity Address, Country	HK
Entity Central Index Key	0001329394
Entity Address, City or Town	Hong Kong Island
Entity Incorporation, State or Country Code	E9
Entity Common Stock, Shares Outstanding	134,244,840
Entity Address, Postal Zip Code	0000
ICFR Auditor Attestation Flag	true
Auditor Name	Deloitte & Touche
Auditor Firm ID	1060
Auditor Location	Taipei, Taiwan
Document Financial Statement Error Correction [Flag]	false
American Depositary Shares
Document Information [Line Items]
Security Exchange Name	NASDAQ
Title of 12(b) Security	American Depositary Shares, each representing four ordinary shares
Trading Symbol	SIMO
Ordinary shares
Document Information [Line Items]
Title of 12(b) Security	Ordinary shares, US$0.01 par value per share
No Trading Symbol Flag	true
Business Contact
Document Information [Line Items]
Entity Address, Address Line One	690 N. McCarthy Blvd., Suite 200
Entity Address, Country	US
Entity Address, City or Town	Milpitas
Entity Address, State or Province	CA
Contact Personnel Fax Number	1 408 519 7101
Country Region	1
City Area Code	408
Local Phone Number	519 7200
Entity Address, Postal Zip Code	95035
Contact Personnel Name	Jason Tsai

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Summary of Income Before Income Tax Is Comprised

Income before income tax is comprised of the following:


	Year Ended December 31
	2023			2024			2025
	US$			US$			US$
Cayman		(17,082	)		(5,305	)		(21,802	)
Income recorded in Hong Kong		23,741			34,983			14,208
Income from other foreign operations		54,389			77,731			147,721

Income before taxes		61,048			107,409			140,127

Summary of Components of Income Tax Provision

The components of income tax provision (benefit) were as follows:


	Year Ended December 31
	2023			2024			2025
	US$			US$			US$
Current taxes:
Hong Kong taxes — current		3,983			5,428			1,728
Foreign taxes — current		3,764			13,154			15,937

Total current taxes		7,747			18,582			17,665
Deferred taxes:
Hong Kong taxes — deferred		—			—			—
Foreign taxes — deferred		428			(422	)		(173	)

Total deferred taxes		428			(422	)		(173	)

Income tax expense		8,175			18,160			17,492

Effective tax rate		13.4	%		16.9	%		12.5	%

Summary of Reconciliation of Income Tax Expense on Pretax Income at Statutory Rate and Income Tax Expense

A reconciliation of the Hong Kong statutory rate of 16.5% to the Company’s effective tax rate for the year ended December 31, 2025 was as follows :


	2025
	US$			%
Tax at Hong Kong Statutory Rate		23,121			16.5
Other Jurisdiction Tax Effects
Cayman Islands
Statutory tax rate difference between Hong Kong and Cayman Islands		(3,482	)		(2.5	)
Nontaxable or nondeductible items		7,078			5.1
Other		290			0.2
Macau
Statutory tax rate difference between Hong Kong and Macau		(2,075	)		(1.5	)
Other		(131	)		(0.1	)
China
Statutory tax rate difference between Hong Kong and China		3,154			2.3
Tax Credits		(4,825	)		(3.4	)
Changes in Valuation Allowances		762			0.5
Other		(202	)		(0.1	)
U.S.
Statutory tax rate difference between Hong Kong and U.S.		(1,855	)		(1.3	)
Changes in Valuation Allowances		2,589			1.9
Other		31			0.0
Other Foreign Jurisdictions
Statutory tax rate difference between Hong Kong and Other Foreign Jurisdictions		1,046			0.8
Other		638			0.5
Changes in Unrecognized Tax Benefits		(8,647	)		(6.2	)

Provision for income taxes and effective tax rate		17,492			12.5

A reconciliation of the Company’s income tax expense at Cayman statutory rate and provision for income tax prior to adoption of ASU 2023-09 is shown below:


	2023			2024
	US$			US$
Tax expense at Cayman statutory rate		—			—
Differences between Cayman and other statutory tax rates		9,979			16,107
Permanent differences		206			365
Temporary differences		(1,614	)		(2,703	)
Alternative minimum tax		1			1
Income tax on undistributed earnings		—			193
Net changes in income tax credit		(205	)		(101	)
Net changes in valuation allowance of deferred income tax assets		3,260			5,014
Net operating loss carryforwards		(1,805	)		497
Liabilities related to unrealized tax benefits		5,482			(42	)
Adjustment of prior years’ taxes and others		(7,129	)		(1,171	)

Income tax expense		8,175			18,160

Summary of Income Tax Paid By Individual Jurisdiction

The following table presents income taxes paid, net of refunds received, for the year ended December 31, 2025.


	Year ended December 31, 2025
	US$
Hong Kong		5,729
Macau		10,078
Others		906

Total income tax paid, net of refunds		16,713

Summary of Deferred Income Tax Assets (Liabilities)

Significant components of our deferred tax assets (liabilities) at the end of each period are as follows:


	December 31
	2024			2025
	US$			US$
Stock-based compensation		1,520			3,090
Allowance for sales return		1,024			472
Inventory reserve		3,122			1,939
Foreign currency translation		(126	)		7
Property and equipment		(628	)		(568	)
Investment tax credits		3,596			3,603
Net operating loss carryforwards		21,607			24,636
Others		6,563			7,228
Valuation allowance		(27,800	)		(31,356	)

Net deferred tax assets		8,878			9,051

Summary of Reconciliation of Unrecognized Tax Benefits

A reconciliation of the beginning and ending balances of the total amounts of unrecognized tax benefits is as follows:


	Year Ended December 31
	2023			2024			2025
	US$			US$			US$
Balance, beginning of year		37,105			43,764			43,584
Increases in tax positions taken in current year		16,054			4,376			6,328
Decrease in tax position taken in prior year primarily related to the resolution of tax audit		(9,395	)		(4,556	)		(14,654	)

Balance, end of year		43,764			43,584			35,258

Summary of Major Jurisdictions and Tax Year Subject to Examination by Tax Authorities


Tax Jurisdiction		Tax Years
China		2022 and onward
Hong Kong		2022 and onward
Taiwan		2020 and onward
United States		2020 onward

Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	$ 885,627	$ 803,552	$ 639,142
China
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	495,107	331,664	229,037
JAPAN
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	123,870	143,130	36,431
Singapore
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	78,432	144,595	127,642
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	74,629	58,114	74,284
Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	22,551	73,057	48,633
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	7,966	13,019	55,504
Others
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	$ 83,072	$ 39,973	$ 67,611

- Definition

+ References

+ Details

Property And Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Gain loss on disposition of assets	$ 0	$ 0	$ (230)
Capitalized contract cost, net	67,038
Shanghai Property
Property, Plant and Equipment [Line Items]
Net carrying value of leased properties	8,636	8,655
Sales-type lease, Residual value of leased asset	$ 782	$ 2,354
Taiwan
Property, Plant and Equipment [Line Items]
Gain loss on disposition of assets			$ 594
Land \| Taiwan
Property, Plant and Equipment [Line Items]
Total consideration				$ 58,931

Change In Allowances (Detail) - USD ($) $ in Thousands	12 Months Ended
Change In Allowances (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Allowances for doubtful accounts
Balance, beginning of year	$ 5	$ 20	$ 569
Additions (reversals) charged to expense, net	(4)	(15)	(549)
Balance, end of year	$ 1	$ 5	$ 20

Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Land	$ 67,640	$ 67,640
Buildings	95,481	28,507
Machinery and equipment	85,851	75,326
Furniture and fixtures	12,707	9,506
Leasehold and buildings improvement	33,707	9,590
Software	82,403	69,854
Total	377,789	260,423
Accumulated Depreciation	159,584	135,279
Prepayment and construction in progress	761	63,254
Property and equipment, net	218,966	188,398	$ 167,417
Software
Property, Plant and Equipment [Line Items]
Accumulated Depreciation	76,943	62,680
Buildings
Property, Plant and Equipment [Line Items]
Accumulated Depreciation	8,347	7,172
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Accumulated Depreciation	61,433	51,791
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Accumulated Depreciation	6,635	7,148
Leasehold and buildings improvement
Property, Plant and Equipment [Line Items]
Accumulated Depreciation	$ 6,226	$ 6,488

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2025

Property, Plant and Equipment [Abstract]

Property and Equipment


	December 31
	2024		2025
	US$		US$
Cost:
Land		67,640		67,640
Buildings		28,507		95,481
Machinery and equipment		75,326		85,851
Furniture and fixtures		9,506		12,707
Leasehold and buildings improvement		9,590		33,707
Software		69,854		82,403

Total		260,423		377,789

Accumulated depreciation:
Buildings		7,172		8,347
Machinery and equipment		51,791		61,433
Furniture and fixtures		7,148		6,635
Leasehold and buildings improvement		6,488		6,226
Software		62,680		76,943

		135,279		159,584
Prepayment and construction in progress		63,254		761

		188,398		218,966

Income Taxes - Reconciliation of Income Tax Expense on Pretax Income at Statutory Rate and Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Reconciliation Of Income Taxes [Line Items]
Differences between Cayman and other statutory tax rates		$ 16,107	$ 9,979
Permanent differences		365	206
Temporary differences		(2,703)	(1,614)
Alternative minimum tax		1	1
Income tax on undistributed earnings		193	0
Net changes in income tax credit		(101)	(205)
Net changes in valuation allowance of deferred income tax assets		5,014	3,260
Net operating loss carryforwards		497	(1,805)
Liabilities related to unrealized tax benefits		(42)	5,482
Adjustment of prior years' taxes and others		(1,171)	(7,129)
Income tax expense	$ 17,492	18,160	8,175
Tax at Hong Kong Statutory Rate	16.50%
Tax at Hong Kong Statutory Rate, Amount	$ 23,121
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount		16,107	9,979
Other, Amount		(1,171)	(7,129)
Changes in Valuation Allowances, Amount		$ 5,014	$ 3,260
Changes in Unrecognized Tax Benefits ,Percent	(0.062)
Changes in Unrecognized Tax Benefits ,Amount	$ (8,647)
Effective Income Tax Rate Reconciliation, Percent	12.50%	16.90%	13.40%
Income Tax Expense (Benefit)	$ 17,492	$ 18,160	$ 8,175
Cayman Island
Reconciliation Of Income Taxes [Line Items]
Differences between Cayman and other statutory tax rates	(3,482)
Adjustment of prior years' taxes and others	$ 290
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	(2.50%)
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	$ (3,482)
Nontaxable or nondeductible items, Percent	5.10%
Nontaxable or nondeductible items, Amount	$ 7,078
Other, Percent	0.20%
Other, Amount	$ 290
Macau
Reconciliation Of Income Taxes [Line Items]
Differences between Cayman and other statutory tax rates	(2,075)
Adjustment of prior years' taxes and others	$ (131)
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	(1.50%)
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	$ (2,075)
Other, Percent	(0.10%)
Other, Amount	$ (131)
China
Reconciliation Of Income Taxes [Line Items]
Differences between Cayman and other statutory tax rates	3,154
Net changes in valuation allowance of deferred income tax assets	762
Adjustment of prior years' taxes and others	$ (202)
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	2.30%
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	$ 3,154
Other, Percent	(0.10%)
Other, Amount	$ (202)
Tax Credits, Percent	3.40%
Tax Credits, Amount	$ 4,825
Changes in Valuation Allowances, Percent	0.50%
Changes in Valuation Allowances, Amount	$ 762
U.S
Reconciliation Of Income Taxes [Line Items]
Differences between Cayman and other statutory tax rates	(1,855)
Net changes in valuation allowance of deferred income tax assets	2,589
Adjustment of prior years' taxes and others	$ 31
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	(1.30%)
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	$ (1,855)
Other, Percent	0.00%
Other, Amount	$ 31
Changes in Valuation Allowances, Percent	1.90%
Changes in Valuation Allowances, Amount	$ 2,589
Other Foreign Jurisdictions
Reconciliation Of Income Taxes [Line Items]
Differences between Cayman and other statutory tax rates	1,046
Adjustment of prior years' taxes and others	$ 638
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	0.80%
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	$ 1,046
Other, Percent	0.50%
Other, Amount	$ 638

Table of Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 26,283	$ 16,956	$ 17,547
Cost of Sales
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	411	311	406
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	17,874	11,284	11,709
Selling and Marketing Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	3,428	1,954	1,858
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 4,570	$ 3,407	$ 3,574

Pension Plan - Additional Information (Detail) - SMI Taiwan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions and Recognized Pension Costs under Labor Pension Act	$ 4,386	$ 3,542	$ 3,369
Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of Contribution by an Employer to Employees Pension	6.00%

Cash, Cash Equivalents, and Restricted Cash

12 Months Ended

Dec. 31, 2025

Cash and Cash Equivalents [Abstract]

Cash, Cash Equivalents, and Restricted Cash

3. CASH, CASH EQUIVALENTS, AND RESTRICTED CASH


	December 31
	2024		2025
	US$		US$
Cash and deposits in bank		29,386		54,964
Time deposits		246,682		143,375
Repurchase agreements		—		3,503

Total cash and cash equivalents		276,068		201,842
Restricted cash		58,265		75,239

		334,333		277,081

As of December 31, 2025 and 2024, restricted cash of US$71,297 thousand and US$54,645 thousand was classified as restricted assets-current, and US$3,942 thousand and US$3,620 thousand was classified as other assets, respectively.

Accounts Receivable

12 Months Ended

Dec. 31, 2025

Receivables [Abstract]

Accounts Receivable

4. ACCOUNTS RECEIVABLE


	December 31
	2024			2025
	US$			US$
Trade accounts receivable		233,749			211,547
Allowance for doubtful accounts		(5	)		(1	)

		233,744			211,546

The changes in the allowances are summarized as follows:


	Year Ended December 31
	2023			2024			2025
	US$			US$			US$
Allowances for doubtful accounts
Balance, beginning of year		569			20			5
Additions (reversals) charged to expense, net		(549	)		(15	)		(4	)

Balance, end of year		20			5			1