GCT Semiconductor Holding (GCTS) 10-Q 14 May 24 2024 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2024	May 10, 2024
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-41013
Entity Registrant Name	GCT Semiconductor Holding, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-2171699
Entity Address, Address Line One	2290 North 1st Street, Suite 201
Entity Address, City or Town	San Jose
Entity Address State Or Province	CA
Entity Address, Postal Zip Code	95131
City Area Code	408
Local Phone Number	434-6040
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		45,890,164
Entity Central Index Key	0001851961
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false
Class A common stock
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	GCTS
Security Exchange Name	NYSE
Warrants, each whole warrant exercisable for one share
Title of 12(b) Security	Warrants, each whole warrant exercisable for one share of Common Stock for $11.50 per share
Trading Symbol	GCTSW
Security Exchange Name	NYSE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents		$ 16,122	$ 258
Accounts receivable, net		5,103	4,920
Inventory		1,784	1,486
Contract assets		4,313	3,439
Prepaid expenses and other current assets		5,466	2,906
Total current assets		32,788	13,009
Property and equipment, net		644	772
Operating lease right-of-use assets		1,343	1,521
Intangibles, net		187	245
Other assets		857	881
Total assets		35,819	16,428
Current liabilities:
Accounts payable		1,242	17,814
Contract liabilities		35	48
Accrued and other current liabilities		25,152	23,956
Borrowings		39,840	44,509
Convertible promissory notes, current		5,645	27,794
Operating lease liabilities, current		679	680
Total current liabilities		72,593	114,801
Convertible promissory notes, net of current		4,672	6,239
Net defined benefit liabilities		7,488	7,689
Long-term operating lease liabilities		674	850
Income taxes payable		2,096	2,178
Warrant liabilities		10,584
Other liabilities		72	108
Total liabilities		98,179	131,865
Commitments and contingencies (Note 8)
Stockholders' deficit:
Preferred stock, par value $0.0001 per share; 40,000 and 82,352 shares authorized as of March 31, 2024 and December 31, 2023, respectively; no shares issued and outstanding as of March 31, 2024 and December 31, 2023
Common stock, par value $0.0001 per share; 400,000 and 200,000 shares authorized as of March 31, 2024 and December 31, 2023, respectively; 45,833 and 24,166 shares issued and outstanding as of March 31, 2024 and December 31, 2023, respectively(1)	[1]	5	3
Additional paid-in capital(1)	[1]	487,006	435,752
Accumulated other comprehensive loss		(474)	(1,538)
Accumulated deficit		(548,897)	(549,654)
Total stockholders' deficit		(62,360)	(115,437)	[1]
Total liabilities and stockholders' deficit		$ 35,819	$ 16,428
[1] Amounts as of December 31, 2023 differ from those in prior year consolidated financial statements as they were retrospectively adjusted as a result of the accounting for the Business Combination (as defined in the Notes to the Unaudited Condensed Consolidated Financial Statements.)

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Condensed Consolidated Balance Sheets
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	40,000,000	82,352,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	400,000,000	200,000,000
Common stock, shares issued	45,833,000	24,166,000
Common stock, shares outstanding	45,833,000	24,166,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Net revenues:
Total net revenues		$ 3,265,000	$ 3,062,000
Cost of net revenues:
Total cost of net revenues		1,312,000	1,541,000
Gross profit		1,953,000	1,521,000
Operating expenses:
Research and development		5,521,000	902,000
Sales and marketing		996,000	836,000
General and administrative		2,836,000	1,477,000
Gain on extinguishment of liability		(14,636,000)
Total operating (income) expenses		(5,283,000)	3,215,000
Income (loss) from operations		7,236,000	(1,694,000)
Interest expense		(2,082,000)	(935,000)
Other (expenses) income, net		(4,338,000)	1,286,000
Income (loss) before provision for income taxes		816,000	(1,343,000)
Provision for income taxes		59,000	50,000
Net income (loss)		757,000	(1,393,000)
Net loss attributable to common stockholders		757,000	(1,393,000)
Net income (loss), diluted		$ 757,000	$ (1,393,000)
Net income (loss) per common share - basic	[1]	$ 0.03	$ (0.06)
Net income (loss) per common share - diluted	[1]	$ 0.03	$ (0.06)
Weighted-average common shares outstanding, basic	[1]	25,468	23,862
Weighted-average shares used in computing net income (loss) per common shares - diluted	[1]	26,257	23,862
Product
Net revenues:
Total net revenues		$ 2,378,000	$ 599,000
Cost of net revenues:
Total cost of net revenues		654,000	978,000
Service
Net revenues:
Total net revenues		887,000	2,463,000
Cost of net revenues:
Total cost of net revenues		$ 658,000	$ 563,000
[1] Amounts as of December 31, 2023 differ from those in prior year consolidated financial statements as they were retrospectively adjusted as a result of the accounting for the Business Combination (as defined in the Notes to the Unaudited Condensed Consolidated Financial Statements.)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Comprehensive income (loss), net of taxes:
Net income (loss)	$ 757	$ (1,393)
Foreign currency translation adjustment	1,064	674
Comprehensive income (loss)	$ 1,821	$ (719)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Deficit - USD ($) shares in Thousands, $ in Thousands		Common Stock Previously reported	Common Stock Revision of prior period, adjustment	Common Stock		Additional Paid-in Capital Previously reported	Additional Paid-in Capital Revision of prior period, adjustment	Additional Paid-in Capital		Accumulated Other Comprehensive Income (Loss) Previously reported	Accumulated Other Comprehensive Income (Loss)		Accumulated Deficit Previously reported	Accumulated Deficit		Previously reported	Total
Balance as at beginning at Dec. 31, 2022		$ 128	$ (126)	$ 2	[1]	$ 433,990	$ 126	$ 434,116	[1]	$ (1,862)	$ (1,862)	[1]	$ (527,185)	$ (527,185)	[1]	$ (94,929)	$ (94,929)	[1]
Balance as at beginning (in shares) at Dec. 31, 2022		127,761	(103,900)	23,861	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options	[1]							1									1
Issuance of common stock upon exercise of stock options (in shares)	[1]			5
Stock-based compensation	[1]							2									2
Foreign currency translation adjustment											674						674
Net income (loss)														(1,393)			(1,393)
Balance as at end at Mar. 31, 2023	[1]			$ 2				434,119			(1,188)			(528,578)			(95,645)
Balance as at end (in shares) at Mar. 31, 2023	[1]			23,866
Balance as at beginning at Dec. 31, 2023		$ 129	$ (126)	$ 3	[1]	$ 435,626	$ 126	435,752	[1]	$ (1,538)	(1,538)	[1]	$ (549,654)	(549,654)	[1]	$ (115,437)	$ (115,437)	[1]
Balance as at beginning (in shares) at Dec. 31, 2023		129,396	(105,230)	24,166	[1]												24,166
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reverse recapitalization transaction, net of transaction costs and acquired liabilities				$ 2				50,031									$ 50,033
Reverse recapitalization transaction, net of transaction costs and acquired liabilities (in shares)				21,667
Stock-based compensation								1,223									1,223
Foreign currency translation adjustment											1,064						1,064
Net income (loss)														757			757
Balance as at end at Mar. 31, 2024				$ 5				$ 487,006			$ (474)			$ (548,897)			$ (62,360)
Balance as at end (in shares) at Mar. 31, 2024				45,833													45,833
[1] Amounts as of December 31, 2023 differ from those in prior year consolidated financial statements as they were retrospectively adjusted as a result of the accounting for the Business Combination (as defined in the Notes to the Unaudited Condensed Consolidated Financial Statements.)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating activities:
Net income (loss)	$ 757	$ (1,393)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	206	225
Operating lease right-of-use amortization	176	168
Finance lease right-of-use amortization		4
Stock-based compensation	1,223	2
Provision for credit losses	247
Gain on extinguishment of liability	(14,636)
Change in valuation of convertible promissory notes	1,203	(549)
Change in valuation of warrant liabilities	4,626
Changes in operating assets and liabilities:
Accounts receivable	(501)	2,144
Inventory	(298)	(651)
Contract assets	(874)	(1,769)
Prepaid expenses and other current assets	(2,292)	102
Other assets	24	35
Accounts payable	(2,713)	133
Contract liabilities	(13)	(650)
Accrued and other current liabilities	(1,067)	1,048
Net defined benefit liabilities	109	186
Income tax payable	(83)
Lease liabilities	(177)	(170)
Other liabilities	(330)	(345)
Net cash used in operating activities	(14,413)	(1,480)
Investing activities:
Purchases of property and equipment		(118)
Net cash used in investing activities		(118)
Financing activities:
Proceeds from exercise of stock options		1
Proceeds from bank borrowings		582
Proceeds from issuance of convertible promissory notes	16,290
Proceeds from reverse recapitalization and PIPE Financing, net of transaction costs	17,238
Repayment of bank borrowings	(3,254)	(31)
Net cash provided by financing activities	30,274	552
Effect of exchange rate changes on cash and cash equivalents	3	(52)
Net increase (decrease) in cash and cash equivalents	15,864	(1,098)
Cash and cash equivalents at beginning of year	258	1,398
Cash and cash equivalents cash at end of year	16,122	300
Supplemental disclosure of cash flow information:
Cash paid for interest	1,183	368
Cash paid for income taxes	3	3
Cash paid for amounts included in the measurement of operating leases	192	$ 195
Issuance of common stock from conversion of convertible promissory notes and accrued interest	$ 41,209

Organization and Liquidity

Organization and Liquidity	3 Months Ended
	Mar. 31, 2024
Organization and Liquidity
Organization and Liquidity	1. Description of Business GCT Semiconductor Holdings, Inc. (formerly known as Concord Acquisition Corp III) and its wholly owned subsidiaries (collectively “GCT”, or the “Company”) is headquartered in San Jose, California with international offices in Korea, China, Taiwan, and Japan. The Company is a fabless semiconductor company that specializes in the design, manufacturing and sale of communication semiconductors, including high-speed wireless communication technologies such as 5G/4.75G/4.5G/4G transceivers and modems, which are essential for a wide variety of industrial, B2B and consumer applications. On March 26, 2024 (the “Closing Date” or “Closing”), Concord Acquisition Corp III (“Concord III”), a Delaware corporation, consummated a series of transactions that resulted in the combination of Gibraltar Merger Sub Inc., a Delaware corporation and a wholly-owned subsidiary of Concord III (“Merger Sub”), and GCT Semiconductor, Inc. (hereinafter referred to as “Legacy GCT”), pursuant to a Business Combination Agreement, dated November 2, 2023 (as amended, the “Business Combination Agreement”), by and among Concord III, Merger Sub and Legacy GCT. Pursuant to the terms of the Business Combination Agreement, Merger Sub merged with and into Legacy GCT, with Legacy GCT surviving the merger as a wholly-owned subsidiary of Concord III (the “Business Combination”). On the Closing Date, Concord III changed its name from Concord III to “GCT Semiconductor Holding, Inc.” The Business Combination was accounted for as a reverse recapitalization with Legacy GCT being the accounting acquirer and Concord III as the acquired company for accounting purposes. Accordingly, all historical financial information presented in the unaudited condensed consolidated financial statements represent the accounts of Legacy GCT. Pursuant to the Business Combination Agreement, the shares and net loss per common share prior to the Closing have been retroactively restated as shares reflecting the exchange ratio established in the Closing of approximately 0.1868. Prior to the Business Combination, Concord III’s public shares, and public redeemable warrants, were listed on the New York Stock Exchange (“NYSE”) under the symbols “CNDB.U,” “CNDB” and “CNDB.WS,” respectively. On March 27, 2024, the Company’s common stock and public warrants began trading on the NYSE, under the symbols “GCTS” and “GCTSW,” respectively. See Note 3 for additional information. In connection with the Closing, Concord III’s Class A common stock and Class B common stock were recapitalized into a single class of common stock. Liquidity The accompanying condensed consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and liabilities and commitments in the normal course of business. Prior to March 31, 2024, the Company has incurred operating losses and negative cash flows from operating and had an accumulated deficit of $548.9 million as of March 31, 2024. The Company’s existing sources of liquidity as of March 31, 2024 include cash and cash equivalents of $16.1 million. The Company has historically funded operations primarily with issuances of capital stock and the incurrence of debt. The Company received $17.2 million in cash proceeds from the reverse recapitalization and PIPE Financing (as defined in Note 3), net of transaction costs. The Company believes the proceeds received in connection with the Business Combination and other capital resources available to the Company including sales of products and services and the

Summary of Significant Accounti

Summary of Significant Accounting Policies and Basis of Presentation	3 Months Ended
	Mar. 31, 2024
Summary of Significant Accounting Policies and Basis of Presentation
Summary of Significant Accounting Policies and Basis of Presentation	2. Principles of Consolidation and Basis of Presentation The condensed consolidated financial statements and accompanying notes include the accounts of the Company and its wholly owned subsidiaries, after elimination of intercompany balances and transactions. The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and the requirements of the Securities and Exchange Commission (“SEC”) for interim financial information. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2023, which are included in the Company’s Form 8-K filed with the SEC on April 1, 2024. The information as of December 31, 2023 included in the condensed consolidated balance sheets was derived from those audited consolidated financial statements. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s financial information. The condensed consolidated results of operations for the three months ended March 31, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other future annual or interim period. Use of Estimates The preparation of the accompanying condensed consolidated financial statements in conformity with U.S. GAAP requires management to make judgments, estimates, and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenues and expenses. These judgments, estimates and assumptions are used for but not limited to revenue recognition, provision for credit losses, inventory obsolescence, recoverability of long-lived assets, certain accrued expenses, stock-based compensation, determination of fair value of the Company’s convertible promissory notes, common stock (prior to the reverse recapitalization), warrant labilities and stock options, and deferred income taxes including related valuation allowances. The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. However, actual results could differ from these estimates, and these differences may be material. Fair Value of Financial Instruments The carrying amount of certain financial instruments held by the Company, such as cash equivalents, accounts receivable, contract assets and liabilities, accounts payable, and accrued and other current liabilities, approximate fair value due to their short maturities. The carrying amount of the liabilities for the convertible promissory notes represents their fair value. The carrying amounts of the Company’s bank borrowings and lease liabilities approximate fair value due to the market interest rates that these obligations bear and interest rates available to the Company. Fair value is defined as the exchange price that would be received for an asset or an exit price paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy defines a three-level valuation hierarchy for disclosure of fair value measurements as follows: Level 1 Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 Inputs other than quoted prices included within Level 1 that are observable, unadjusted quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities. Level 3 Unobservable inputs that are supported by little or no market activity for the related assets or liabilities. The categorization of a financial instrument within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company’s Level 3 financial instruments consist of convertible promissory notes and warrant liabilities. These financial instruments were valued using valuation techniques that are considered to be a Level 3 fair value measurement . Risk and Uncertainties The Company is subject to certain risks and uncertainties and believes changes in any of the following areas could have a material adverse effect on the Company’s future financial position or results of operations or cash flows: new product development, including market receptivity, the ability to satisfy obligations under development agreements with major partners, litigation or claims against the Company based on intellectual property, patent, product regulation or other factors, competition from other products, general economic conditions, the ability to attract and retain qualified employees and ultimately to sustain profitable operations. The semiconductor industry is characterized by rapid technological change, competition, competitive pricing pressures and cyclical market patterns. The Company’s financial results are affected by a wide variety of factors, such as general economic conditions specific to the semiconductor industry and the Company’s particular market, the timely implementation of new products, new manufacturing process technologies and the ability to safeguard patents and intellectual property in a rapidly evolving market. In addition, the semiconductor market has historically been cyclical and subject to significant economic downturns. As a result, the Company may experience significant period-to-period fluctuations in condensed consolidated operating results due to the factors mentioned above or other factors. The Company’s revenue may be impacted by its ability to obtain adequate wafer supplies from foundries and back-end production capacity from the Company’s test and assembly subcontractors. The foundries with which the Company currently has arrangements may not be willing or able to satisfy all of the Company’s manufacturing requirements on a timely basis and/or at favorable prices. The Company is also subject to the risks of service disruptions, raw material shortages and price increases by its foundries. Such disruptions, shortages and price increases could harm the Company’s consolidated operating results. Provision for Credit Losses The provision for credit losses is based on the Company’s assessment of the collectability of its customer accounts. The Company reviews the provision for credit losses by considering certain factors such as historical experience, industry data, credit quality, age of balances and current economic conditions that may affect a customer’s ability to pay. Uncollectible receivables are written off when all efforts to collect have been exhausted and recoveries are recognized when they are recovered. The Company determined that provisions for credit losses of approximately $1.9 million and $1.6 million were necessary as of March 31, 2024 and December 31, 2023, respectively. Concentration of Credit Risk Financial instruments that potentially subject the Company to the concentration of credit risk consist of cash and cash equivalents and accounts receivable. The Company maintains its cash and cash equivalents primarily with one financial institution located in the United States and another financial institution located in Korea where amounts deposited may exceed Federal Deposit Insurance Corporation or Korea Deposit Insurance Corporation limits. The Company’s accounts receivable balances are primarily derived from revenues earned from customers located in the United States, China, Korea, Japan and Taiwan. The Company performs ongoing credit evaluations of its customers’ and distributors’ financial condition and generally does not require collateral from its customers. The Company’s net revenue and accounts receivable are concentrated among a few significant customers, which could expose the Company to financial risk in the event of adverse developments with these customers. Four customers accounted for approximately 28 percent, 19 percent, 18 percent and 13 percent of the Company’s gross accounts receivable as of March 31, 2024. Four customers accounted for approximately 27 percent, 19 percent, 14 percent and 10 percent of the Company’s gross accounts receivable as of December 31, 2023. Two customers accounted for approximately 61 percent and 24 percent of the Company’s total net revenues for the three months ended March 31, 2024. Four customers accounted for approximately 28 percent, 28 percent, 25 percent, and 10 percent of the Company’s total net revenues for the three months ended March 31, 2023. Management closely monitors the creditworthiness and performance of these key customers and has established credit limits and terms to mitigate potential credit risks. The Company also continues to diversify its customer base and explore opportunities to reduce its reliance on a few major customers. Foreign Currency Financial statements of foreign subsidiaries that use the local currency as their functional currency are translated into U.S. dollars at the end-of-period exchange rates or at historical exchange rates for purposes of consolidation. Revenues and expenses are translated using average exchange rates during the period. Translation adjustments are included in accumulated other comprehensive loss within stockholders’ deficit. Gains and losses resulting from transactions denominated in a currency other than the functional currency are included in other income, net in the condensed consolidated statements of operations. The Company recognized $1.1 million and $0.7 million foreign currency exchange gains for the three months ended March 31, 2024 and 2023, respectively. Convertible Promissory Notes The Company has elected the fair value option to account for its outstanding convertible promissory notes. Under the fair value option, the convertible promissory notes must be recorded at their initial fair value on the date of issuance, any modification, and at the end of each reporting period end date thereafter. Changes in the estimated fair value of the convertible promissory notes are recognized as non-cash gains or losses in other income, net in the condensed consolidated statements of operations. Contracts in Equity The Company classifies contracts in equity, including warrants to purchase shares of the Company’s common stock, that do not meet the indexation guidance as liabilities. At the end of each reporting period, such liability classified instruments are remeasured and changes in fair value during the reporting period are recognized within the condensed consolidated statements of operations until the earlier of the exercise, settlement, or expiration. The Company classifies contracts in equity, including the Legacy GCT Earnouts and Sponsor Earnouts (discussed in Note 3), that meet the indexation and equity classification guidance as a component of stockholders’ deficit and are not subject to fair value remeasurements. Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS” Act). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act, until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, these condensed consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. Recent Accounting Pronouncements Adopted In August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) Contracts in Entity’s Own Equity (Subtopic 815-40) In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 805) Recent Accounting Pronouncements Not Yet Adopted In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820) In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280) In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740)

Reverse Recapitalization

Reverse Recapitalization	3 Months Ended
	Mar. 31, 2024
Reverse Recapitalization
Reverse Recapitalization	3. In connection with the Business Combination described in Note 1, Concord III completed the acquisition of Legacy GCT and acquired 100% of Legacy GCT’s common stock. Legacy GCT received net proceeds of $17.1 million from the PIPE Financing (as defined below). Concord III incurred total direct transaction costs of $13.1 million, which were expensed by Concord III, and of which $0.9 million related to the PIPE Financing. Legacy GCT incurred transaction costs of $8.9 million, consisting of legal, accounting, and other professional fees, which were recorded as additional paid-in capital. Each share of Legacy GCT capital stock received a deemed value of $10.00 per share after giving effect to the applicable exchange ratio of 0.1868. Upon Closing of the Business Combination, the following occurred: ● Each share of Legacy GCT common stock issued and outstanding prior to the Closing was cancelled and converted into the right to receive a number of shares of the Company common stock at the exchange ratio of 0.1868 . ● Each outstanding instrument of Legacy GCT stock options, restricted stock units (“RSUs”) and warrant shares were converted into equivalent Company stock options, RSUs and warrant shares with the same terms and conditions and at the exchange ratio of 0.1868 . ● Certain GCT convertible promissory notes, including the CVT Financing (see Note 7), were automatically converted into the right to receive a number of shares of the Company common stock at the conversion price of $6.67 per share (see Note 7). The number of shares of common stock issued and outstanding immediately following consummation of the Business Combination was (in thousands): ​ ​ ​ ​ Shares Common stock of Concord III outstanding prior to the Business Combination 3,941 Less: redemption of Concord III’s common stock (3,766) Sponsor earnout common stock outstanding prior to the Business Combination 8,625 Common stock of Concord III issued and outstanding 8,800 Common stock issued in PIPE Financing 4,530 Legacy GCT common stock 32,503 Total common stock issued and outstanding 45,833 ​ The Business Combination was accounted for as a reverse recapitalization under U.S. GAAP because Legacy GCT was determined to be the accounting acquirer under the FASB’s Accounting Standards Codification (“ASC”) Topic 805, Business Combinations Legacy GCT was determined to be the accounting acquirer based on evaluation of the following facts and circumstances: ● Legacy GCT stockholders comprise a relative majority of the voting power of GCT; ● Legacy GCT stockholders have the ability to nominate a majority of the members of the board of directors of GCT; ● Legacy GCT’s operations prior to the Business Combination will comprise the only ongoing operations of GCT; ● Legacy GCT’s senior management comprises the senior management of GCT; ● GCT substantially assuming the Legacy GCT name; ● Legacy GCT’s headquarters will become GCT’s headquarters; and ● Concord III did not meet the definition of a business. PIPE Financing Concurrent with the execution of the Business Combination Agreement, certain investors (the “PIPE Investors”) entered into subscription agreements (the “PIPE Subscription Agreements”) pursuant to which the PIPE Investors had committed to purchase in a private placement an aggregate of 4,529,967 shares of Company’s Common Stock (the “PIPE Shares”) at a purchase price of $6.67 per share for an aggregate purchase price of $30.2 million (the “PIPE Financing”). The purchase of the PIPE Shares was conditioned upon the consummation of the Business Combination. The PIPE Financing was consummated immediately prior to the Closing. The Company received net proceeds of $17.1 million from the PIPE Financing. Private Placement Warrants and Public Warrants In November 2021, Concord III issued warrants to purchase shares of Concord III’s common stock that were assumed by the Company at the Closing of the Business Combination on the same terms and conditions: (i) 9,400,000 warrant shares that were issued in a private placement and held by the sponsor and another company (the “private placement warrants”) and (ii) 17,250,000 warrant shares that were issued in connection with the initial public offering of Concord III (the “public warrants”). Collectively these warrant shares are referred to as “private and public warrants” and included settlement provisions that precluded equity classification. The private placement warrants were reallocated at the Closing of the Business Combination as follows: (i) 4,492,650 warrants were vested and retained by the sponsor parties, (ii) 2,087,350 warrants were reallocated from the sponsor parties to certain recipients at Legacy GCT’s discretion to incentivize investment, and (iii) 2,820,000 were forfeited by the sponsor parties. The Company has historically accounted for the private and public warrants as liability-classified financial instruments. This conclusion is based on the applicable provisions of the private and public warrants, including their settlement terms upon a change in control or similar transactions that precluded equity classification. After the Closing, the private and public warrants remained liability-classified as the applicable provisions did not change and apply to future operations of the Company. Legacy GCT Earnout Shares At the Closing of the Business Combination, former Legacy GCT stockholders and other investors of Legacy GCT have the right to receive up to an aggregate of 20,000,000 shares of Company common stock (“Earnout Shares”), if at any time during the period starting 60 trading days following the Closing and expiring on the 5 th In the event of a future transaction that results in a change in control in which shares of Company common stock are converted into the right to receive cash or other consideration having a value equal to or in excess of a triggering event, then the Legacy GCT Earnout Shares subject to the applicable triggering event that have not been previously issued will be issued to the Legacy GCT stockholders effective as of immediately prior to the consummation of such transaction. In the event of a transaction that results in a change in control in which shares of Company common stock are converted into the right to receive cash or other consideration having a value less than a triggering event, then the Earnout Shares subject to the applicable triggering event that have not been previously issued will be forfeited. The Legacy GCT Earnout shares have been recognized at fair value of approximately $108.8 million upon the Closing and classified within stockholders’ deficit as the Legacy GCT Earnout shares are indexed to the common stock and are otherwise not precluded from equity classification based on their settlement provisions. The fair value of the Legacy GCT Earnout Shares was determined based on a valuation using a Monte Carlo simulation with key inputs and assumptions such as stock price, term, dividend yield, risk-free rate, and volatility. Due to the fact that the Company does not have any retained earnings, the Company recorded Sponsor Earnout Shares Concurrently with entering into the Business Combination Agreement, the sponsor parties and the Company entered into that certain sponsor support agreement, as amended, modified or supplemented (the “Sponsor Support Agreement”). Pursuant to the terms of the Sponsor Support Agreement, the sponsor parties have the right to receive an aggregate of 1,920,375 shares of the Company common stock multiplied by the Sponsor Earnout Ratio (as defined in the Sponsor Support Agreement) (“Sponsor Earnout Shares”), if at any time during the period starting 6 months following the Closing and expiring on the 5 th one one one The Sponsor Earnout Shares have been recognized at fair value of approximately $10.4 million upon the Closing and classified within stockholders’ deficit as the Sponsor Earnout Shares are indexed to the common stock and are otherwise not precluded from equity classification based on their settlement provisions. The fair value of the Sponsor Earnout Shares was determined based on a valuation using a Monte Carlo simulation with key inputs and assumptions such as stock price, term, dividend yield, risk-free rate, and volatility. Since the Business Combination is accounted for as a reverse recapitalization, the issuance of the Sponsor Earnout Shares are treated as a deemed dividend. Since the Company does not have retained earnings, the issuance of the Sponsor Earnout Shares at the Closing is recorded within additional paid-in capital and has a net nil impact on stockholders’ deficit during the period ended March 31, 2024. In future reporting periods, the Company will monitor that the Sponsor Earnout shares meet the equity classification criteria until expiration or settlement.

Disaggregation of Revenue

Disaggregation of Revenue	3 Months Ended
	Mar. 31, 2024
Disaggregation of Revenue
Disaggregation of Revenue	4. Disaggregation of revenues from contracts with customers is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, 2024 ​ Product Revenues Service Revenues Total Timing of revenue recognition ​ ​ ​ ​ At a point in time ​ $ 2,378 ​ $ — ​ $ 2,378 Over time ​ — ​ 887 ​ 887 Total ​ $ 2,378 ​ $ 887 ​ $ 3,265 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, 2023 ​ Product Revenues Service Revenues Total Timing of revenue recognition ​ ​ ​ At a point in time ​ $ 599 ​ $ — ​ $ 599 Over time ​ — ​ 2,463 ​ 2,463 Total ​ $ 599 ​ $ 2,463 ​ $ 3,062 ​ Net revenues categorized by customer location are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2024 ​ 2023 Korea ​ $ 2,000 ​ $ — Germany ​ 796 ​ — United States ​ 389 ​ 1,968 China ​ 80 ​ 1,094 Total ​ $ 3,265 ​ $ 3,062 ​ Contract Assets and Liabilities Details of contract assets and liabilities is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 Contract assets ​ $ 4,313 ​ $ 3,439 Assets recognized for costs incurred to fulfill a contract (*) ​ 13 ​ 12 Contract liabilities ​ 35 ​ 48 (*) The balances are included in prepaid expenses and other current assets in the accompanying condensed consolidated balance sheets. Net revenues recognized in relation to contract liabilities are as follows as of the periods indicated (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 March 31, 2023 Net revenues recognized that were included in the contract liabilities balance at the beginning of the period ​ $ 12 ​ $ 650 ​

Fair Value of Measurements

Fair Value of Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value of Measurements
Fair Value of Measurements	5. Fair value hierarchy classifications of the financial instruments that are measured at fair value on a recurring basis are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 ​ Level 1 Level 2 Level 3 Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible promissory notes ​ $ — ​ $ — ​ $ 10,317 ​ $ 10,317 Warrant liabilities ​ — ​ — ​ 10,584 ​ 10,584 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ Level 1 Level 2 Level 3 Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible promissory notes ​ $ — ​ $ — ​ $ 34,033 ​ $ 34,033 ​ Valuation techniques and the inputs The table below presents valuation techniques and inputs used in the fair value measurement categorized within Level 3 of the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Valuation techniques Inputs March 31, 2024 December 31, 2023 Convertible promissory notes, current Discounted Cash Flow Model (“DCF”) Discount rate, risk-free rate, credit spread, contractual cash flows ​ $ 5,645 ​ ​ ​ ​ ​ PWERM (“Probability-Weighted Expected Return Method”) ​ Scenario of initial public offering (“IPO”) and merger & acquisition (“M&A”) ​ ​ ​ ​ $ 27,794 Convertible promissory notes, net of current Binomial Lattice Model (“BLM”) Stock price, volatility, remaining term, risk-free rate, credit spread ​ 4,672 ​ ​ ​ ​ PWERM ​ Scenario of initial public offering (“IPO”) and merger & acquisition (“M&A”) ​ ​ ​ ​ ​ 6,239 Warrant liabilities – private and public warrants Black Scholes Merton Model (“BSM”) or BLM Exercise price, term to expiration, volatility, risk-free rate ​ 9,150 ​ — Warrant liabilities - other ​ ​ ​ ​ 1,434 ​ — ​ As of March 31, 2024, the key inputs for the convertible promissory notes, current using the DCF were as follows: remaining term of 0.25 years and a discount rate of 10.2%. As of March 31, 2024, the key inputs for the convertible promissory notes, net of current using the BLM were as follows: stock price of $6.58, volatility of 32.2%, remaining term of 1.9 years, risk-free rate of 4.6%, and credit spread of 5.0%. As of March 31, 2024, the key inputs for the private placement warrants using the BSM were as follows: exercise price of $11.50 per share, term to expiration of 5 years, volatility range of 19.4% and a risk-free rate of 4.2%. As of March 31, 2024, the key inputs for the public warrants using the BLM were as follows: exercise price of $11.50 per share and term to expiration of 5.0 years. As of March 31, 2024, the key inputs for the warrant liabilities – other using the BSM were as follows: an exercise price of $5.00 per share, or $10.00 per share or $18.75 per share, term to expiration ranging from 0.4 years to 2.6 years, volatility ranging from 29.5% to 32.7%, and a risk-free rate ranging from 4.4% to 5.4%. As of December 31, 2023, the PWERM was used as Legacy GCT was a private company. After the Closing, and as of March 31, 2024, the valuation techniques used reflect that the Business Combination was consummated. The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Convertible promissory notes fair value - beginning of period ​ $ 34,033 ​ $ 31,166 Change in fair value of convertible promissory notes ​ 1,203 ​ (549) Conversion of convertible promissory notes ​ (41,209) ​ — Borrowing of convertible promissory notes ​ 16,290 ​ — Convertible promissory notes fair value - end of period ​ $ 10,317 ​ $ 30,617 ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Warrant Liabilities Fair value - beginning of period ​ $ — ​ $ — Private and public warrants assumed at Closing ​ 5,958 ​ — Change in fair value of warrant liabilities ​ 4,626 ​ — Warrant Liabilities Fair value - end of period ​ $ 10,584 ​ $ — ​ The gains and losses from fair value re-measurement of Level 3 financial liabilities are recorded as other income, net in the condensed consolidated statements of operations.

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2024
Balance Sheet Components
Balance Sheet Components	6. Inventory Inventories consists of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2024 ​ 2023 Raw materials ​ $ 414 ​ $ 448 Work-in-process ​ 498 ​ 601 Finished goods ​ 872 ​ 437 Total inventory ​ $ 1,784 ​ $ 1,486 ​ There were no write-downs of inventory into cost of net revenues for the three months ended March 31, 2024 and 2023. Prepaid expenses and other assets Prepaid expenses and other assets consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2024 ​ 2023 Prepaid expenses ​ $ 3,345 ​ $ 433 Prepaid inventory ​ ​ 1,429 ​ ​ 279 Lease deposit ​ 413 ​ 434 Other receivables and current assets ​ 279 ​ 117 IPO expenses ​ — ​ 1,643 Prepaid expenses and other current assets ​ $ 5,466 ​ $ 2,906 ​ Accrued and other current liabilities Accrued and other current liabilities consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2024 ​ 2023 Payroll and related expenses ​ $ 9,830 ​ $ 9,880 Accrued payables ​ ​ 7,853 ​ ​ 6,319 Other taxes payable ​ ​ 3,399 ​ ​ 158 Current portion of interest payable ​ ​ 3,395 ​ ​ 6,915 Professional fees ​ 444 ​ 499 Royalty and license fee ​ 60 ​ 58 Product warranty ​ 64 ​ 55 Other ​ 107 ​ 72 Accrued and other current liabilities ​ $ 25,152 ​ $ 23,956 ​

Debt

Debt	3 Months Ended
	Mar. 31, 2024
Debt
Debt	7. The Company’s outstanding debt was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ Principal ​ Fair Value ​ Principal ​ Fair Value Convertible promissory notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Historical convertible promissory notes ​ $ 5,630 ​ $ 5,645 ​ $ 35,347 ​ $ 34,033 2023 & 2024 convertible promissory notes ​ 5,000 ​ 4,672 ​ — ​ — Borrowings: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ KEB Hana Bank ​ 6,682 ​ 6,682 ​ 6,980 ​ 6,980 IBK Industrial Bank ​ 6,831 ​ 6,831 ​ 7,135 ​ 7,135 Note payable (one individual investor) ​ 1,000 ​ 1,000 ​ 1,000 ​ 1,000 M-Venture Investment, Inc. ​ 7,425 ​ 7,425 ​ 7,756 ​ 7,756 Anapass, Inc, related party ​ 9,653 ​ 9,653 ​ 10,082 ​ 10,082 i Best Investment Co., Ltd ​ 7,425 ​ 7,425 ​ 10,082 ​ 10,082 Kyeongho Lee, related party ​ 824 ​ 824 ​ 1,474 ​ 1,474 Total debt ​ $ 50,470 ​ 50,157 ​ $ 79,856 ​ 78,542 Less: current portion ​ ​ ​ ​ (45,485) ​ ​ ​ ​ (72,303) Debt, net of current portion ​ ​ ​ ​ $ 4,672 ​ ​ ​ ​ $ 6,239 ​ The Company elected the fair value option for the 2023 & 2024 convertible promissory notes and the historical convertible promissory notes (see Note 5). The Company’s other borrowings approximate their fair value because interest rates are at prevailing market rates and/or the short-term nature of the remaining obligations. See Note 14 for additional information on related parties. Expected future minimum principal payments under the Company’s total debt is as follows as of March 31, 2024 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible ​ ​ ​ ​ ​ ​ Notes ​ ​ ​ ​ ​ ​ Years ​ Payable ​ Borrowing ​ Total 2024, remainder ​ $ 5,630 ​ $ 39,840 ​ $ 45,470 2025 ​ — ​ — ​ — 2026 ​ 5,000 ​ — ​ 5,000 Total debt ​ $ 10,630 ​ $ 39,840 ​ $ 50,470 ​ Convertible Promissory Notes Historical Convertible Promissory Notes Between 2017 and 2022, the Company issued convertible promissory notes to various investors with maturity dates ranging from October 2020 to April 2025. The annual interest rates varied between 4.0% and 7.0%. In November 2023, the Company entered into an amendment with certain convertible promissory noteholders to modify the conversion terms such that these notes were automatically convertible upon a special purpose acquisition company (“SPAC”) transaction. In March 2024, upon the Closing of the Business Combination, an aggregate principal and interest amount of $32.1 million converted into 4,258,223 shares of common stock at a conversion price of $10.00. As of March 31, 2024, the remaining principal and interest amount of $7.9 million was outstanding and related to two noteholders where conversion is at each noteholder’s discretion and at a conversion price of $3.50 per share. In April 2024, the Company repaid one of the convertible promissory notes (see Note 17). 2023 & 2024 Convertible Promissory Notes In November 2023, February 2024 and March 2024, the Company issued convertible promissory notes to certain investors (the “CVT Investors”), pursuant to which the CVT Investors agreed to lend to the Company an aggregate principal amount of $13.3 million. These notes had maturity dates ranging from November 2026 to March 2027, bore an interest rate of 5.0% and were automatically convertible upon IPO or SPAC transaction. In March 2024, upon the Closing of the Business Combination, an aggregate principal and interest amount of $13.4 million converted into 2,004,535 shares of common stock at a conversion price of $6.67. As of March 31, 2024, none of the notes issued to CVT Investors remain outstanding. In February 2024, the Company issued a convertible promissory note to a strategic investor for a principal amount of $5.0 million, which matures in February 2026 and bears an interest rate of 5.0% per annum. On or after the earlier of (i) six months from the issuance date of the convertible promissory note and (ii) the Closing of the Business Combination, the noteholder may demand that the Company convert all principal and interest due under the convertible promissory note into shares of Company’s common stock, at a conversion price of $10.00 per share. This note includes customary representations, warranties, and events of default, as well as a covenant relating to the performance of obligations by the Company related to the Company’s 5G activity. As of March 31, 2024, the remaining principal and interest amount of $5.0 million was outstanding. Borrowings Pursuant to Term Loan and Security Agreements KEB Hana Bank In July 2016, the Company entered into an unsecured term loan agreement with KEB Hana Bank pursuant to which it borrowed KRW 9.0 billion ($6.7 million), bearing a variable interest rate (2.6% initial annual interest rate and 5.2% as of March 31, 2024), paid monthly, and maturing in July 2017. The terms of such unsecured term loan agreement have been extended annually for additional one-year terms since 2017, and the maturity date is July 2024. Anapass, Inc., a related party, provided certificates of deposit as collateral to KEB Hana Bank to secure the Company’s obligations under this loan (see Note 8). As of March 31, 2024, the remaining principal and interest amount of $6.7 million was outstanding. IBK Industrial Bank In January 2017, the Company entered into a term loan agreement with IBK Industrial Bank pursuant to which the Company borrowed KRW 9.2 billion ($6.8 million). The term loan has a maturity date in November 2024 and bears an annual interest rate of 4.9%. As of March 31, 2024, the remaining principal and interest amount of $6.8 million was outstanding. Note Payable (One Individual Investor) In June 2021, the Company entered into a note payable agreement with an individual investor pursuant to which the Company borrowed $1.0 million. The note has a maturity date in June 2024 and bears an annual interest rate of 4.0%. In April 2022, the Company entered into an amendment with this one individual investor to remove the conversion right from the note payable. As of March 31, 2024, the remaining principal and interest amount of $1.1 million was outstanding. M-Venture Investment, Inc. In October 2021, the Company entered into a term loan and security agreement with M-Venture Investment, Inc. pursuant to which the Company borrowed KRW 5.0 billion ($3.7 million) and repaid KRW 0.6 billion ($0.4 million) and KRW 0.4 billion ($0.3 million) in 2021 and 2022, respectively, such that KRW 4.0 billion ($3.0 million) remained outstanding. The term loan has a maturity date in October 2024 and bears an annual interest rate of 6.5%. As of March 31, 2024, the remaining principal and interest amount of $3.1 million was outstanding. In April 2022, the Company entered into a term loan and security agreement with M-Venture Investment, Inc. pursuant to which the Company borrowed amounts in two draws of KRW 1.0 billion ($0.7 million) and KRW 5.0 billon ($3.7 million), respectively. The term loan has a maturity date in April 2024 and each respective draw bears an annual interest rate of 6.5% and 8.7%. As of March 31, 2024, the remaining principal and interest amount of $4.8 million was outstanding. In April 2024, the Company executed amendments with M-Venture Investment, Inc. (see Note 17). Anapass, Inc., Related Party In July 2016, the Company entered into a loan agreement with Anapass, Inc. pursuant to which the Company borrowed KRW 6.0 billion ($4.5 million) in a term loan. Interest only payments are due monthly at 5.5% per annum and the principal amount of the term loan is due on the maturity date of July 2024. The loan is collateralized by the Company’s assets as described under the Assets Pledged as Collateral (see Note 8). As of March 31, 2024, the remaining principal and interest amount of $4.5 million was outstanding. In May and September 2022, the Company entered into two term loan agreements with Anapass, Inc. pursuant to which the Company borrowed KRW 3.0 billion ($2.2 million) and KRW 4.0 billion ($3.0 million) in term loans. The term loans have respective maturity dates in May 2024 and September 2024 and both bear an annual interest rate of 5.5%. As of March 31, 2024, the remaining principal and interest amount of $5.2 million was outstanding. i Best Investment Co., Ltd From 2022 and 2023, the Company entered into multiple term loans and security agreements with i Best Investment Co., Ltd pursuant to which it borrowed principal amounts in six draws with an aggregate principal balance of KRW 14.0 billion ($10.3 million). All of the term loans have a maturity date in June 2024 and bear an annual interest rate of 6.5%. In December 2023, the Company made a $0.8 million repayment of the outstanding principal and interest on its second draw. In March 2024, the Company made a $2.3 million repayment of the outstanding principal and interest amount of its fourth draw. As of March 31, 2024, the remaining principal and interest amounts outstanding were as follows: $3.3 million outstanding on its first draw, $1.6 million outstanding on its third draw, $2.3 million outstanding on its fifth draw and $0.8 million on its sixth draw. Kyeongho Lee, Related Party From 2017 and 2021, the Company entered into multiple promissory note and term loan agreements with Kyeongho Lee pursuant to which the Company borrowed (a) KRW 500.0 million ($0.4 million), and KRW 500.0 million ($0.4 million) in promissory notes, and (b) KRW 1.0 billion ($0.7 million) and KRW 110.0 million ($0.1 million) in term loans. The promissory notes have a maturity date in November 2024 and bear an annual interest rate varying from 7.5% and 9.0%. During the three months ended March 31, 2024, the Company repaid in full one of the term loans. The term loan has a maturity date in May 2024 and bears an annual interest rate of 0.0%. As of March 31, 2024, the remaining principal and interest amount of $0.7 million and $82,000 was outstanding as it related to the promissory notes and a term loan, respectively.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies.
Commitments and Contingencies	8. Litigation The Company is subject to various claims arising in the ordinary course of business. Although no assurance can be given, the Company believes that it is not a party to any litigation of which the outcome, if determined adversely, would individually, or in the aggregate, be reasonably expected to have a material adverse effect on the business, consolidated operating results, cash flows or financial position of the Company as of March 31, 2024. Third parties have from time to time claimed, and others may claim in the future, that the Company has infringed their past, current or future intellectual property rights. These claims, whether meritorious or not, could be time consuming, result in costly litigation, require expensive changes in the Company’s methods of doing business or could require the Company to enter into costly royalty or licensing agreements, if available. As a result, these claims could harm the Company’s business, consolidated operating results, cash flows, and financial position. Purchase Commitment The Company has certain commitments for outstanding purchase orders related to the manufacture of certain wafers utilized by the Company and other services that, once the wafers are placed into production, are noncancelable. Otherwise, these production agreements are cancellable at any time with the Company required to pay all costs incurred through the cancellation date. However, the Company has rarely cancelled these agreements once production has started. As of March 31, 2024, the Company had no outstanding noncancelable purchase commitments for these production agreements. In July 2020, the Company entered into a research and development agreement with Samsung Electronics Co., Ltd (“Samsung”). According to the agreement, the Company would design 5G chip products and Samsung would provide development and intellectual property support, mass production set up support including mask sets for manufacturing and engineering sample chip supply to the Company for a specific product. The total fee amount for the research and development (“R&D”) services pursuant to the agreement was $21.1 million. The Company bore the risk of R&D failure and was obligated to pay the $21.1 million total fee based on milestones defined in the agreement, of which $11.7 million was due based on development milestones and $9.4 million of additional NRE (“non-recurring engineering”) was to be paid within a maximum of 4 years In February 2024, the Company and Alpha Holdings Co., Ltd. (“Alpha”) entered into a foundry product development agreement related to 5G chip development for a total fee of $7.6 million. The Company bears the risk of R&D failure and is obligated to pay the fee based on milestones defined in the agreement. The Company recognizes R&D expenses based on an estimate of the percentage completion of services provided by Alpha during the respective financial reporting period. For the three months ended March 31, 2024, the Company recorded $3.5 million in R&D expenses related to services provided by Alpha. The aggregate unpaid amount related to this agreement is $5.0 million as of March 31, 2024. Assets Pledged as Collateral The Company has provided collateral to Anapass, Inc., a related party (see Note 14), for borrowings from KEB Hana Bank, IBK Industrial Bank and Anapass, Inc. in the amount of $6.7 million, $6.8 million and $9.7 million, respectively, as of March 31, 2024, and $7.0 million, $7.1 million and $10.1 million, respectively, as of December 31, 2023 (see Note 7). The following table includes a summary of the collateral provided to Anapass, Inc. (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, Secured ​ ​ 2024 ​ 2023 ​ Creditor Cash and cash equivalents ​ $ 16,122 ​ $ 254 ​ ​ Accounts receivable ​ ​ 5,118 ​ ​ 4,920 ​ Inventory ​ 1,784 ​ 1,486 Anapass, Inc. Property and equipment ​ 1,988 ​ 352 Intangible assets and others ​ 187 ​ 199 ​

Common Stock

Common Stock	3 Months Ended
	Mar. 31, 2024
Common Stock
Common Stock	9. In connection with the Closing of the Business Combination, the Company increased its total number of authorized shares to 440,000,000 shares, consisting of 400,000,000 shares of common stock and 40,000,000 shares of preferred stock. The Company has reserved shares of common stock for issuance as follows (in thousands): ​ ​ ​ ​ ​ ​ March 31 December 31 ​ ​ 2024 ​ 2023 Warrants ​ 26,724 ​ 2,894 Shares available for future grant from 2024 plan ​ 3,983 ​ — Convertible promissory notes 800 1,835 Options issued and outstanding 668 668 Shares available for future grant from 2024 ESPP 600 — RSUs outstanding 392 392 Shares available for future grant from 2011 plan — 113 Total 33,167 5,902 ​

Warrants

Warrants	3 Months Ended
	Mar. 31, 2024
Warrants
Warrants	10. The following table represents a summary of warrants to purchase shares of the Company’s common stock that are outstanding (in thousands, except for exercise price): ​ ​ ​ ​ ​ ​ ​ Issue Date March 31, 2024 Exercise Price Expiration August 2021 ​ 299 ​ $ 10.00 - $18.75 ​ (1) September 2021 300 ​ $ 5.00 (1) February 2023 - June 2023 2,115 ​ $ 10.00 - $18.75 (1) July 2023 80 ​ $ 10.00 (1) October 2023 100 ​ $ 10.00 (1) Private and public warrants 23,830 ​ $ 11.50 ​ March 26, 2029 Tota l 26,724 ​ ​ (1) Within 3 years from the date of issuance. See Note 3 with respect to further details on the private and public warrants and Note 5 with respect to valuation techniques and assumptions because the warrants are all liability-classified and subject to fair value measurement each reporting period.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2024
Stock-Based Compensation
Stock-Based Compensation	11. 2011 Incentive Compensation Plan Legacy GCT’s 2011 Incentive Compensation Plan (the “2011 Plan”) permitted the grant of options, stock awards, and RSUs. In connection with the Closing of the Business Combination, the 2011 Plan was terminated, the remaining unallocated shares reserved under the 2011 Plan were cancelled and no new awards will be granted under the 2011 Plan. Each award of Legacy GCT stock options and RSUs were converted into equivalent Company stock options and RSUs with the same terms and conditions under the plan described below. 2024 Incentive Compensation Plan In connection with the Closing of the Business Combination, the Company adopted the 2024 Incentive Compensation Plan (the “2024 Plan”) under which 3,983,334 shares of common stock were initially reserved for issuance, subject to approval by the Company’s boards of directors. The 2024 Plan permits the grant of stock options, stock appreciation rights, stock awards, restricted stock units, dividend equivalent right, cash awards and other awards to employees, non-employee directors, non-employee members of the board of directors, or consultants or independent advisors. Stock options outstanding under the 2024 Plan were as follows (in thousands, except per share amounts and years): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ Number of ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ Options ​ Average ​ Contractual Life ​ Aggregated ​ ​ Outstanding ​ Exercise Price ​ (in Years) ​ Intrinsic Value Balance as of December 31, 2023 ​ 3,579 ​ $ 0.02 ​ 5.5 ​ $ 4,405 Reverse recapitalization ​ (2,911) ​ ​ 0.09 ​ — ​ ​ — Balance as of December 31, 2023 (1) ​ 668 ​ $ 0.11 ​ 5.5 ​ ​ 4,405 Granted ​ — ​ ​ — ​ — ​ ​ — Exercised ​ — ​ ​ — ​ — ​ ​ — Cancelled ​ — ​ ​ — ​ — ​ ​ — Balance as of March 31, 2024 668 ​ 0.11 5.3 ​ 5,543 Vested as of March 31, 2024 667 ​ $ 0.11 5.3 ​ 5,532 Exercisable as of March 31, 2024 634 ​ $ 0.11 5.1 ​ 5,256 (1) Amounts as of December 31, 2023 differ from those in prior year consolidated financial statements as they were retrospectively adjusted as a result of the accounting for the Business Combination (see Note 3). There were no options granted during the three months ended March 31, 2024 and 2023. As of March 31, 2024, unrecognized compensation cost related to stock options was nominal. Founder Awards to Board of Directors In 2021, an aggregate of 90,000 founder shares of common stock were transferred to three members of Concord III’s board of directors. The shares contained both a performance condition based upon a liquidity event and a service vesting condition. As the liquidity and services conditions were met upon the Closing of the Business Combination, the Company recognized $0.9 million of stock-based compensation during the three months ended March 31, 2024. Restricted Stock Units In December 2023, various employees and directors of Legacy GCT were granted RSUs that contain both a performance condition based upon a liquidity event and a service vesting condition such that the RSUs vest in four equal annual installments from the grant date. Any unvested RSUs are forfeited upon separation from the Company. The liquidity condition was met upon the Closing of the Business Combination and the Company recognized $0.3 million of stock-based compensation. RSUs outstanding under the 2024 Plan were as follows (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number of RSUs ​ Average Grant ​ ​ Outstanding ​ Date Fair Value Balance as of December 31, 2023 ​ 2,100 ​ $ 1.15 Reverse recapitalization ​ (1,708) ​ ​ 5.01 Balances as of December 31, 2023 (1) ​ 392 ​ $ 6.16 Granted — ​ — Vested — ​ — Cancelled — ​ — Balance as of March 31, 2024 392 ​ $ 6.16 (1) Amounts as of December 31, 2023 differ from those in prior year consolidated financial statements as they were retrospectively adjusted as a result of the accounting for the Business Combination (see Note 3). As of March 31, 2024, there was $2.1 million of unrecognized compensation cost related to RSUs, which is expected to be recognized on a straight-line basis over a weighted average period of 3.7 years.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Taxes
Income Taxes	12. For the three months ended March 31, 2024 and 2023, the Company recorded income tax expense of $59,000 and $50,000, respectively. The effective tax rate is 7.2% and 3.7% for the three months ended March 31, 2024 and 2023, respectively. For financial reporting purposes, the Company’s effective tax rate used for the interim periods is based on the estimated full-year income tax rate. For the three months ended March 31, 2024, the Company’s effective tax rate differs from the statutory rate primarily due to the valuation allowance recorded against the net deferred tax asset balance. As of March 31, 2024 the Company had unrecognized tax benefits of $3.1 million of which $1.7 million would currently affect the Company’s effective tax rate if recognized due to the Company’s deferred tax assets being fully offset by a valuation allowance. The Company does not anticipate that the amount of unrecognized tax benefits relating to tax positions existing as of March 31, 2024 will significantly increase or decrease within the next twelve months. There was no interest expense or penalties related to unrecognized tax benefits recorded as of March 31, 2024. A number of years may elapse before an uncertain tax position is audited and finally resolved. While it is often difficult to predict the final outcome or the timing of resolution of any particular uncertain tax position, the Company believes that its reserves for income taxes reflect the most likely outcome. The Company adjusts these reserves, as well as the related interest, in light of changing facts and circumstances. Settlement of any particular position could require the use of cash. Currently the Company is not under examination by any taxing authority.

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2024
Employee Benefit Plans
Employee Benefit Plans	13. Under Korean law, the Company is required to make severance payments to Korean employees leaving its employment. The Company’s severance pay liability to its Korean employees, which is a function of the salary of each employee’s years of employment and severance factor, is reflected in the accompanying condensed consolidated balance sheets as the net defined benefit liabilities on an accrual basis. The net liability for severance payments as of (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 Liability for severance payments, beginning ​ $ 7,764 ​ $ 7,997 Deposit ​ (276) ​ (308) Liability for severance payments, ending ​ $ 7,488 ​ $ 7,689 ​

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2024
Related Party Transactions
Related Party Transactions	14. A summary of balances and transactions with the related parties who are stockholders of the Company were as follows as of (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 ​ ​ Anapass Kyeongho Lee ​ Anapass Kyeongho Lee Borrowings ​ $ 9,653 ​ $ 824 ​ $ 10,082 ​ $ 1,474 Other current liabilities ​ 106 ​ 87 ​ 212 ​ 182 ​ For each of the three months ended March 31, 2024 and 2023, the Company recorded $0.1 million of interest expense with Anapass, Inc. in the condensed consolidated statements of operations. During the three months ended March 31, 2024 and 2023, the Company recorded $22,000 and $26,000, respectively, of interest expense with Kyeongho Lee in the condensed consolidated statements of operations.

Segments and Information

Segments and Information	3 Months Ended
	Mar. 31, 2024
Segments and Information
Segments and Information	15. The Company operates in one segment. Revenue information by geographic region is presented in Note 4 to these condensed consolidated financial statements. Long-lived assets by geographic region were as follows as of (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 South Korea ​ $ 1,170 ​ $ 1,363 United States ​ 817 ​ 930 Total long-lived assets ​ $ 1,987 ​ $ 2,293 ​

Net Income (Loss) Per Share

Net Income (Loss) Per Share	3 Months Ended
	Mar. 31, 2024
Net Income (Loss) Per Share
Net Income (Loss) Per Share	16. The following table summarizes the computation of basic and diluted net income (loss) per share (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Numerator: ​ ​ Net income (loss), basic and diluted ​ $ 757 ​ $ (1,393) Denominator: ​ ​ Weighted-average common shares outstanding, basic ​ 25,468 ​ 23,862 Add: effect of dilutive securities ​ 789 ​ — Weighted-average common shares outstanding, diluted ​ 26,257 ​ 23,862 Net income (loss) per share, basic and diluted ​ ​ Basic ​ $ 0.03 ​ $ (0.06) Diluted ​ $ 0.03 ​ $ (0.06) ​ The following outstanding potentially dilutive common stock equivalents were excluded from the computation of diluted net income (loss) per share for the periods indicated because including them would have been antidilutive (in thousands): ​ ​ ​ ​ ​ ​ March 31, ​ ​ 2024 2023 Warrants 26,724 995 Convertible promissory notes 5,543 1,809 Options — 885 Total 32,267 3,689 ​

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2024
Subsequent Events
Subsequent Events	17. Purchase Agreement and Registration Rights Agreement In April 2024, the Company entered into a common stock purchase agreement (the “Purchase Agreement”) and a related registration rights agreement (the “Registration Rights Agreement”) with B. Riley Principal Capital II, LLC (“B. Riley Principal Capital II”). Upon the terms and subject to the satisfaction of the conditions set forth in the Purchase Agreement, the Company has the right, in its sole discretion, to sell to B. Riley Principal Capital II, from time to time, up to $50.0 million in aggregate gross purchase price of shares of the Company’s common stock, subject to certain limitations contained in the Purchase Agreement, during the term of 24 months M-Venture Investment, Inc. In April 2024, the Company executed an amendment with M-Venture Investment, Inc. for the KRW 4.0 billion ($3.0 million) term loan outstanding, pursuant to which the Company repaid KRW 2.0 billion ($1.5 million) in April 2024 and extended the maturity date from October 2024 to May 2024 (see Note 7). In April 2024, the Company executed an amendment with M-Venture Investment, Inc. for the KRW 6.0 billion ($4.4 million) term loan outstanding, pursuant to which the maturity date for both draws were amended. The maturity date for the principal amount of KRW 1.0 billion ($0.7 million) was extended from April 2024 to June 2024. The maturity date for the principal amount of KRW 5.0 billion ($3.7 million) was extended from April 2024 to July 2024 (see Note 7). Historical Convertible Promissory Notes In April 2024, the Company repaid in full a historical convertible promissory note that was issued in 2021 with a principal amount of $0.6 million (see Note 7). Share Reserve In May 2024, the board of directors of the Company approved 3,983,334 shares as the maximum number of shares of Common stock that may be issued pursuant to 2024 Plan, and 600,000 shares as reserved share amount of 2024 Employee Stock Purchase Plan.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2024
Summary of Significant Accounting Policies and Basis of Presentation
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation The condensed consolidated financial statements and accompanying notes include the accounts of the Company and its wholly owned subsidiaries, after elimination of intercompany balances and transactions. The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and the requirements of the Securities and Exchange Commission (“SEC”) for interim financial information. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2023, which are included in the Company’s Form 8-K filed with the SEC on April 1, 2024. The information as of December 31, 2023 included in the condensed consolidated balance sheets was derived from those audited consolidated financial statements. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s financial information. The condensed consolidated results of operations for the three months ended March 31, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other future annual or interim period.
Use of Estimates	Use of Estimates The preparation of the accompanying condensed consolidated financial statements in conformity with U.S. GAAP requires management to make judgments, estimates, and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenues and expenses. These judgments, estimates and assumptions are used for but not limited to revenue recognition, provision for credit losses, inventory obsolescence, recoverability of long-lived assets, certain accrued expenses, stock-based compensation, determination of fair value of the Company’s convertible promissory notes, common stock (prior to the reverse recapitalization), warrant labilities and stock options, and deferred income taxes including related valuation allowances. The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. However, actual results could differ from these estimates, and these differences may be material.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amount of certain financial instruments held by the Company, such as cash equivalents, accounts receivable, contract assets and liabilities, accounts payable, and accrued and other current liabilities, approximate fair value due to their short maturities. The carrying amount of the liabilities for the convertible promissory notes represents their fair value. The carrying amounts of the Company’s bank borrowings and lease liabilities approximate fair value due to the market interest rates that these obligations bear and interest rates available to the Company. Fair value is defined as the exchange price that would be received for an asset or an exit price paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy defines a three-level valuation hierarchy for disclosure of fair value measurements as follows: Level 1 Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 Inputs other than quoted prices included within Level 1 that are observable, unadjusted quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities. Level 3 Unobservable inputs that are supported by little or no market activity for the related assets or liabilities. The categorization of a financial instrument within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company’s Level 3 financial instruments consist of convertible promissory notes and warrant liabilities. These financial instruments were valued using valuation techniques that are considered to be a Level 3 fair value measurement .
Risk and Uncertainties	Risk and Uncertainties The Company is subject to certain risks and uncertainties and believes changes in any of the following areas could have a material adverse effect on the Company’s future financial position or results of operations or cash flows: new product development, including market receptivity, the ability to satisfy obligations under development agreements with major partners, litigation or claims against the Company based on intellectual property, patent, product regulation or other factors, competition from other products, general economic conditions, the ability to attract and retain qualified employees and ultimately to sustain profitable operations. The semiconductor industry is characterized by rapid technological change, competition, competitive pricing pressures and cyclical market patterns. The Company’s financial results are affected by a wide variety of factors, such as general economic conditions specific to the semiconductor industry and the Company’s particular market, the timely implementation of new products, new manufacturing process technologies and the ability to safeguard patents and intellectual property in a rapidly evolving market. In addition, the semiconductor market has historically been cyclical and subject to significant economic downturns. As a result, the Company may experience significant period-to-period fluctuations in condensed consolidated operating results due to the factors mentioned above or other factors. The Company’s revenue may be impacted by its ability to obtain adequate wafer supplies from foundries and back-end production capacity from the Company’s test and assembly subcontractors. The foundries with which the Company currently has arrangements may not be willing or able to satisfy all of the Company’s manufacturing requirements on a timely basis and/or at favorable prices. The Company is also subject to the risks of service disruptions, raw material shortages and price increases by its foundries. Such disruptions, shortages and price increases could harm the Company’s consolidated operating results.
Provision for Credit Losses	Provision for Credit Losses The provision for credit losses is based on the Company’s assessment of the collectability of its customer accounts. The Company reviews the provision for credit losses by considering certain factors such as historical experience, industry data, credit quality, age of balances and current economic conditions that may affect a customer’s ability to pay. Uncollectible receivables are written off when all efforts to collect have been exhausted and recoveries are recognized when they are recovered. The Company determined that provisions for credit losses of approximately $1.9 million and $1.6 million were necessary as of March 31, 2024 and December 31, 2023, respectively.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to the concentration of credit risk consist of cash and cash equivalents and accounts receivable. The Company maintains its cash and cash equivalents primarily with one financial institution located in the United States and another financial institution located in Korea where amounts deposited may exceed Federal Deposit Insurance Corporation or Korea Deposit Insurance Corporation limits. The Company’s accounts receivable balances are primarily derived from revenues earned from customers located in the United States, China, Korea, Japan and Taiwan. The Company performs ongoing credit evaluations of its customers’ and distributors’ financial condition and generally does not require collateral from its customers. The Company’s net revenue and accounts receivable are concentrated among a few significant customers, which could expose the Company to financial risk in the event of adverse developments with these customers. Four customers accounted for approximately 28 percent, 19 percent, 18 percent and 13 percent of the Company’s gross accounts receivable as of March 31, 2024. Four customers accounted for approximately 27 percent, 19 percent, 14 percent and 10 percent of the Company’s gross accounts receivable as of December 31, 2023. Two customers accounted for approximately 61 percent and 24 percent of the Company’s total net revenues for the three months ended March 31, 2024. Four customers accounted for approximately 28 percent, 28 percent, 25 percent, and 10 percent of the Company’s total net revenues for the three months ended March 31, 2023. Management closely monitors the creditworthiness and performance of these key customers and has established credit limits and terms to mitigate potential credit risks. The Company also continues to diversify its customer base and explore opportunities to reduce its reliance on a few major customers.
Foreign Currency	Foreign Currency Financial statements of foreign subsidiaries that use the local currency as their functional currency are translated into U.S. dollars at the end-of-period exchange rates or at historical exchange rates for purposes of consolidation. Revenues and expenses are translated using average exchange rates during the period. Translation adjustments are included in accumulated other comprehensive loss within stockholders’ deficit. Gains and losses resulting from transactions denominated in a currency other than the functional currency are included in other income, net in the condensed consolidated statements of operations. The Company recognized $1.1 million and $0.7 million foreign currency exchange gains for the three months ended March 31, 2024 and 2023, respectively.
Convertible Promissory Notes	Convertible Promissory Notes The Company has elected the fair value option to account for its outstanding convertible promissory notes. Under the fair value option, the convertible promissory notes must be recorded at their initial fair value on the date of issuance, any modification, and at the end of each reporting period end date thereafter. Changes in the estimated fair value of the convertible promissory notes are recognized as non-cash gains or losses in other income, net in the condensed consolidated statements of operations.
Contracts in Equity	Contracts in Equity The Company classifies contracts in equity, including warrants to purchase shares of the Company’s common stock, that do not meet the indexation guidance as liabilities. At the end of each reporting period, such liability classified instruments are remeasured and changes in fair value during the reporting period are recognized within the condensed consolidated statements of operations until the earlier of the exercise, settlement, or expiration. The Company classifies contracts in equity, including the Legacy GCT Earnouts and Sponsor Earnouts (discussed in Note 3), that meet the indexation and equity classification guidance as a component of stockholders’ deficit and are not subject to fair value remeasurements.
Emerging Growth Company Status	Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS” Act). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act, until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, these condensed consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.
Recent Accounting Pronouncements Adopted	Recent Accounting Pronouncements Adopted In August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) Contracts in Entity’s Own Equity (Subtopic 815-40) In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 805) Recent Accounting Pronouncements Not Yet Adopted In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820) In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280) In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740)

Reverse Recapitalization (Table

Reverse Recapitalization (Tables)	3 Months Ended
	Mar. 31, 2024
Reverse Recapitalization
Number of shares of common stock issued and outstanding immediately following consummation of the Business Combination	The number of shares of common stock issued and outstanding immediately following consummation of the Business Combination was (in thousands): ​ ​ ​ ​ Shares Common stock of Concord III outstanding prior to the Business Combination 3,941 Less: redemption of Concord III’s common stock (3,766) Sponsor earnout common stock outstanding prior to the Business Combination 8,625 Common stock of Concord III issued and outstanding 8,800 Common stock issued in PIPE Financing 4,530 Legacy GCT common stock 32,503 Total common stock issued and outstanding 45,833

Disaggregation of Revenue (Tabl

Disaggregation of Revenue (Tables)	3 Months Ended
	Mar. 31, 2024
Organization and Liquidity
Schedule of disaggregation of revenues from contracts with customers and categorized by customer location	Disaggregation of revenues from contracts with customers is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, 2024 ​ Product Revenues Service Revenues Total Timing of revenue recognition ​ ​ ​ ​ At a point in time ​ $ 2,378 ​ $ — ​ $ 2,378 Over time ​ — ​ 887 ​ 887 Total ​ $ 2,378 ​ $ 887 ​ $ 3,265 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, 2023 ​ Product Revenues Service Revenues Total Timing of revenue recognition ​ ​ ​ At a point in time ​ $ 599 ​ $ — ​ $ 599 Over time ​ — ​ 2,463 ​ 2,463 Total ​ $ 599 ​ $ 2,463 ​ $ 3,062 ​ Net revenues categorized by customer location are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2024 ​ 2023 Korea ​ $ 2,000 ​ $ — Germany ​ 796 ​ — United States ​ 389 ​ 1,968 China ​ 80 ​ 1,094 Total ​ $ 3,265 ​ $ 3,062
Schedule of contract assets and liabilities and net revenues recognized in relation to contract liabilities	Details of contract assets and liabilities is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 Contract assets ​ $ 4,313 ​ $ 3,439 Assets recognized for costs incurred to fulfill a contract (*) ​ 13 ​ 12 Contract liabilities ​ 35 ​ 48 (*) The balances are included in prepaid expenses and other current assets in the accompanying condensed consolidated balance sheets.
Schedule of net revenues and gross accounts receivable concentration	Net revenues recognized in relation to contract liabilities are as follows as of the periods indicated (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 March 31, 2023 Net revenues recognized that were included in the contract liabilities balance at the beginning of the period ​ $ 12 ​ $ 650 ​

Fair Value of Measurements (Tab

Fair Value of Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value of Measurements
Schedule of classifications of the financial instruments that are measured at fair value on a recurring basis	Fair value hierarchy classifications of the financial instruments that are measured at fair value on a recurring basis are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 ​ Level 1 Level 2 Level 3 Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible promissory notes ​ $ — ​ $ — ​ $ 10,317 ​ $ 10,317 Warrant liabilities ​ — ​ — ​ 10,584 ​ 10,584 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ Level 1 Level 2 Level 3 Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible promissory notes ​ $ — ​ $ — ​ $ 34,033 ​ $ 34,033
Schedule of valuation techniques and inputs used in the fair value measurement	The table below presents valuation techniques and inputs used in the fair value measurement categorized within Level 3 of the fair value hierarchy (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Valuation techniques Inputs March 31, 2024 December 31, 2023 Convertible promissory notes, current Discounted Cash Flow Model (“DCF”) Discount rate, risk-free rate, credit spread, contractual cash flows ​ $ 5,645 ​ ​ ​ ​ ​ PWERM (“Probability-Weighted Expected Return Method”) ​ Scenario of initial public offering (“IPO”) and merger & acquisition (“M&A”) ​ ​ ​ ​ $ 27,794 Convertible promissory notes, net of current Binomial Lattice Model (“BLM”) Stock price, volatility, remaining term, risk-free rate, credit spread ​ 4,672 ​ ​ ​ ​ PWERM ​ Scenario of initial public offering (“IPO”) and merger & acquisition (“M&A”) ​ ​ ​ ​ ​ 6,239 Warrant liabilities – private and public warrants Black Scholes Merton Model (“BSM”) or BLM Exercise price, term to expiration, volatility, risk-free rate ​ 9,150 ​ — Warrant liabilities - other ​ ​ ​ ​ 1,434 ​ —
Schedule of changes in the fair value of the Company's Level 3 financial liabilities	The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Convertible promissory notes fair value - beginning of period ​ $ 34,033 ​ $ 31,166 Change in fair value of convertible promissory notes ​ 1,203 ​ (549) Conversion of convertible promissory notes ​ (41,209) ​ — Borrowing of convertible promissory notes ​ 16,290 ​ — Convertible promissory notes fair value - end of period ​ $ 10,317 ​ $ 30,617 ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Warrant Liabilities Fair value - beginning of period ​ $ — ​ $ — Private and public warrants assumed at Closing ​ 5,958 ​ — Change in fair value of warrant liabilities ​ 4,626 ​ — Warrant Liabilities Fair value - end of period ​ $ 10,584 ​ $ —

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2024
Balance Sheet Components
Schedule of Inventory	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2024 ​ 2023 Raw materials ​ $ 414 ​ $ 448 Work-in-process ​ 498 ​ 601 Finished goods ​ 872 ​ 437 Total inventory ​ $ 1,784 ​ $ 1,486
Schedule of Prepaid expenses and other assets	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2024 ​ 2023 Prepaid expenses ​ $ 3,345 ​ $ 433 Prepaid inventory ​ ​ 1,429 ​ ​ 279 Lease deposit ​ 413 ​ 434 Other receivables and current assets ​ 279 ​ 117 IPO expenses ​ — ​ 1,643 Prepaid expenses and other current assets ​ $ 5,466 ​ $ 2,906
Schedule of Accrued and other current liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2024 ​ 2023 Payroll and related expenses ​ $ 9,830 ​ $ 9,880 Accrued payables ​ ​ 7,853 ​ ​ 6,319 Other taxes payable ​ ​ 3,399 ​ ​ 158 Current portion of interest payable ​ ​ 3,395 ​ ​ 6,915 Professional fees ​ 444 ​ 499 Royalty and license fee ​ 60 ​ 58 Product warranty ​ 64 ​ 55 Other ​ 107 ​ 72 Accrued and other current liabilities ​ $ 25,152 ​ $ 23,956 ​

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2024
Debt
Schedule of borrowings	The Company’s outstanding debt was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ Principal ​ Fair Value ​ Principal ​ Fair Value Convertible promissory notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Historical convertible promissory notes ​ $ 5,630 ​ $ 5,645 ​ $ 35,347 ​ $ 34,033 2023 & 2024 convertible promissory notes ​ 5,000 ​ 4,672 ​ — ​ — Borrowings: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ KEB Hana Bank ​ 6,682 ​ 6,682 ​ 6,980 ​ 6,980 IBK Industrial Bank ​ 6,831 ​ 6,831 ​ 7,135 ​ 7,135 Note payable (one individual investor) ​ 1,000 ​ 1,000 ​ 1,000 ​ 1,000 M-Venture Investment, Inc. ​ 7,425 ​ 7,425 ​ 7,756 ​ 7,756 Anapass, Inc, related party ​ 9,653 ​ 9,653 ​ 10,082 ​ 10,082 i Best Investment Co., Ltd ​ 7,425 ​ 7,425 ​ 10,082 ​ 10,082 Kyeongho Lee, related party ​ 824 ​ 824 ​ 1,474 ​ 1,474 Total debt ​ $ 50,470 ​ 50,157 ​ $ 79,856 ​ 78,542 Less: current portion ​ ​ ​ ​ (45,485) ​ ​ ​ ​ (72,303) Debt, net of current portion ​ ​ ​ ​ $ 4,672 ​ ​ ​ ​ $ 6,239 ​
Schedule of maturities of borrowings	Expected future minimum principal payments under the Company’s total debt is as follows as of March 31, 2024 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible ​ ​ ​ ​ ​ ​ Notes ​ ​ ​ ​ ​ ​ Years ​ Payable ​ Borrowing ​ Total 2024, remainder ​ $ 5,630 ​ $ 39,840 ​ $ 45,470 2025 ​ — ​ — ​ — 2026 ​ 5,000 ​ — ​ 5,000 Total debt ​ $ 10,630 ​ $ 39,840 ​ $ 50,470

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies.
Schedule of collateral provided to Anapass, Inc	The following table includes a summary of the collateral provided to Anapass, Inc. (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, Secured ​ ​ 2024 ​ 2023 ​ Creditor Cash and cash equivalents ​ $ 16,122 ​ $ 254 ​ ​ Accounts receivable ​ ​ 5,118 ​ ​ 4,920 ​ Inventory ​ 1,784 ​ 1,486 Anapass, Inc. Property and equipment ​ 1,988 ​ 352 Intangible assets and others ​ 187 ​ 199 ​

Common Stock (Tables)

Common Stock (Tables)	3 Months Ended
	Mar. 31, 2024
Common Stock
Summary of shares reserved for shares authorized but unissued common stock	The Company has reserved shares of common stock for issuance as follows (in thousands): ​ ​ ​ ​ ​ ​ March 31 December 31 ​ ​ 2024 ​ 2023 Warrants ​ 26,724 ​ 2,894 Shares available for future grant from 2024 plan ​ 3,983 ​ — Convertible promissory notes 800 1,835 Options issued and outstanding 668 668 Shares available for future grant from 2024 ESPP 600 — RSUs outstanding 392 392 Shares available for future grant from 2011 plan — 113 Total 33,167 5,902 ​

Warrants (Tables)

Warrants (Tables)	3 Months Ended
	Mar. 31, 2024
Warrants
Summary of warrants	The following table represents a summary of warrants to purchase shares of the Company’s common stock that are outstanding (in thousands, except for exercise price): ​ ​ ​ ​ ​ ​ ​ Issue Date March 31, 2024 Exercise Price Expiration August 2021 ​ 299 ​ $ 10.00 - $18.75 ​ (1) September 2021 300 ​ $ 5.00 (1) February 2023 - June 2023 2,115 ​ $ 10.00 - $18.75 (1) July 2023 80 ​ $ 10.00 (1) October 2023 100 ​ $ 10.00 (1) Private and public warrants 23,830 ​ $ 11.50 ​ March 26, 2029 Tota l 26,724 ​ ​ (1) Within 3 years from the date of issuance.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Stock-Based Compensation
Summary of stock option activity	Stock options outstanding under the 2024 Plan were as follows (in thousands, except per share amounts and years): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ Number of ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ Options ​ Average ​ Contractual Life ​ Aggregated ​ ​ Outstanding ​ Exercise Price ​ (in Years) ​ Intrinsic Value Balance as of December 31, 2023 ​ 3,579 ​ $ 0.02 ​ 5.5 ​ $ 4,405 Reverse recapitalization ​ (2,911) ​ ​ 0.09 ​ — ​ ​ — Balance as of December 31, 2023 (1) ​ 668 ​ $ 0.11 ​ 5.5 ​ ​ 4,405 Granted ​ — ​ ​ — ​ — ​ ​ — Exercised ​ — ​ ​ — ​ — ​ ​ — Cancelled ​ — ​ ​ — ​ — ​ ​ — Balance as of March 31, 2024 668 ​ 0.11 5.3 ​ 5,543 Vested as of March 31, 2024 667 ​ $ 0.11 5.3 ​ 5,532 Exercisable as of March 31, 2024 634 ​ $ 0.11 5.1 ​ 5,256 (1) Amounts as of December 31, 2023 differ from those in prior year consolidated financial statements as they were retrospectively adjusted as a result of the accounting for the Business Combination (see Note 3).
Summary of RSUs activity	RSUs outstanding under the 2024 Plan were as follows (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number of RSUs ​ Average Grant ​ ​ Outstanding ​ Date Fair Value Balance as of December 31, 2023 ​ 2,100 ​ $ 1.15 Reverse recapitalization ​ (1,708) ​ ​ 5.01 Balances as of December 31, 2023 (1) ​ 392 ​ $ 6.16 Granted — ​ — Vested — ​ — Cancelled — ​ — Balance as of March 31, 2024 392 ​ $ 6.16 (1) Amounts as of December 31, 2023 differ from those in prior year consolidated financial statements as they were retrospectively adjusted as a result of the accounting for the Business Combination (see Note 3).

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2024
Employee Benefit Plans
Summary of net liability for severance payments	The net liability for severance payments as of (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 Liability for severance payments, beginning ​ $ 7,764 ​ $ 7,997 Deposit ​ (276) ​ (308) Liability for severance payments, ending ​ $ 7,488 ​ $ 7,689 ​

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2024
Related Party Transactions
Summary of balances and transactions with the related parties	A summary of balances and transactions with the related parties who are stockholders of the Company were as follows as of (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 ​ ​ Anapass Kyeongho Lee ​ Anapass Kyeongho Lee Borrowings ​ $ 9,653 ​ $ 824 ​ $ 10,082 ​ $ 1,474 Other current liabilities ​ 106 ​ 87 ​ 212 ​ 182

Segments and Information (Table

Segments and Information (Tables)	3 Months Ended
	Mar. 31, 2024
Segments and Information
Summary of long-lived assets by geographic region	The Company operates in one segment. Revenue information by geographic region is presented in Note 4 to these condensed consolidated financial statements. Long-lived assets by geographic region were as follows as of (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 South Korea ​ $ 1,170 ​ $ 1,363 United States ​ 817 ​ 930 Total long-lived assets ​ $ 1,987 ​ $ 2,293 ​

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Net Income (Loss) Per Share
Summary of computation of basic and diluted net loss per share	The following table summarizes the computation of basic and diluted net income (loss) per share (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Numerator: ​ ​ Net income (loss), basic and diluted ​ $ 757 ​ $ (1,393) Denominator: ​ ​ Weighted-average common shares outstanding, basic ​ 25,468 ​ 23,862 Add: effect of dilutive securities ​ 789 ​ — Weighted-average common shares outstanding, diluted ​ 26,257 ​ 23,862 Net income (loss) per share, basic and diluted ​ ​ Basic ​ $ 0.03 ​ $ (0.06) Diluted ​ $ 0.03 ​ $ (0.06)
Schedule of Potentially dilutive securities that were excluded from the computation of diluted net loss per common share	The following outstanding potentially dilutive common stock equivalents were excluded from the computation of diluted net income (loss) per share for the periods indicated because including them would have been antidilutive (in thousands): ​ ​ ​ ​ ​ ​ March 31, ​ ​ 2024 2023 Warrants 26,724 995 Convertible promissory notes 5,543 1,809 Options — 885 Total 32,267 3,689 ​

Organization and Liquidity (Det

Organization and Liquidity (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 26, 2024	Dec. 31, 2023 USD ($)
Organization and Liquidity
Exchange ratio		0.1868
Accumulated deficit	$ (548,897)		$ (549,654)
Cash and cash equivalents	16,122		$ 258
Cash proceeds from the reverse recapitalization and PIPE Financing	$ 17,238

Summary of Significant Accoun_3

Summary of Significant Accounting Policies and Basis of Presentation - Provision for Credit Losses (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Organization and Liquidity
Provisions for credit losses	$ 1.9	$ 1.6

Summary of Significant Accoun_4

Summary of Significant Accounting Policies and Basis of Presentation - Concentration of Revenues and Accounts Receivable (Details) - customer	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Revenue | Two customers
The Company and Summary of Significant Accounting Policies
Number of customers	2
Revenue | Four customers
The Company and Summary of Significant Accounting Policies
Number of customers		4
Revenue | Customer concentration | Customer A
The Company and Summary of Significant Accounting Policies
Concentration risk percentage	61%	28%
Revenue | Customer concentration | Customer B
The Company and Summary of Significant Accounting Policies
Concentration risk percentage	24%	28%
Revenue | Customer concentration | Customer C
The Company and Summary of Significant Accounting Policies
Concentration risk percentage		25%
Revenue | Customer concentration | Customer D
The Company and Summary of Significant Accounting Policies
Concentration risk percentage		10%
Accounts receivable | Four customers
The Company and Summary of Significant Accounting Policies
Number of customers	4	4
Accounts receivable | Customer concentration | Customer A
The Company and Summary of Significant Accounting Policies
Concentration risk percentage	28%	27%
Accounts receivable | Customer concentration | Customer B
The Company and Summary of Significant Accounting Policies
Concentration risk percentage	19%	19%
Accounts receivable | Customer concentration | Customer C
The Company and Summary of Significant Accounting Policies
Concentration risk percentage	18%	14%
Accounts receivable | Customer concentration | Customer D
The Company and Summary of Significant Accounting Policies
Concentration risk percentage	13%	10%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies and Basis of Presentation - Foreign Currency (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Organization and Liquidity
Foreign currency transactions	$ 1.1	$ 0.7

Reverse Recapitalization - Busi

Reverse Recapitalization - Business Combination (Details) $ / shares in Units, $ in Millions	Mar. 26, 2024 USD ($) $ / shares
Concord III
Reverse Recapitalization [Line Items]
Transaction costs incurred in acquisition	$ 13.1
Concord III | PIPE financing
Reverse Recapitalization [Line Items]
Transaction costs incurred in acquisition	0.9
Legacy G C T
Reverse Recapitalization [Line Items]
Transaction costs incurred in acquisition	$ 8.9
Legacy G C T | Concord III
Reverse Recapitalization [Line Items]
Percentage of ownership acquired	100%
Net proceeds received on acquisition	$ 17.1
Share price in business acquisition | $ / shares	$ 10
Stock exchange ratio	0.1868
Legacy G C T | Concord III | Convertible debt
Reverse Recapitalization [Line Items]
Conversion price | $ / shares	$ 6.67

Reverse Recapitalization - Numb

Reverse Recapitalization - Number of shares of common stock issued and outstanding post Business Combination (Details) - shares shares in Thousands	Mar. 26, 2024	Mar. 31, 2024	Dec. 31, 2023
Reverse Recapitalization
Common stock, shares outstanding		45,833	24,166
Total common stock issued and outstanding	45,833	45,833	24,166
Sponsor Earnout Shares
Reverse Recapitalization
Sponsor earnout common stock outstanding prior to the Business Combination	8,625
PIPE financing
Reverse Recapitalization
Common stock issued in PIPE Financing	4,530
Concord III
Reverse Recapitalization
Common stock, shares outstanding	3,941
Less: redemption of Concord I I I's common stock	(3,766)
Common stock of Concord I I I issued and outstanding	8,800
Legacy G C T
Reverse Recapitalization
Legacy GCT common stock	32,503

Reverse Recapitalization - Reve

Reverse Recapitalization - Reverse Recapitalization (Details)	Mar. 26, 2024 USD ($)
Concord III | Legacy G C T
Reverse Recapitalization [Line Items]
Goodwill and intangible assets	$ 0

Reverse Recapitalization - PIPE

Reverse Recapitalization - PIPE Financing (Details) - PIPE financing $ / shares in Units, $ in Millions	Mar. 26, 2024 USD ($) $ / shares shares
Reverse Recapitalization [Line Items]
Number of shares issued | shares	4,529,967
Issue price per share | $ / shares	$ 6.67
Value of shares issued	$ 30.2
Net proceeds from PIPE financing	$ 17.1

Reverse Recapitalization -Priva

Reverse Recapitalization -Private Warrants and Public warrants (Details) - shares	1 Months Ended	3 Months Ended
	Nov. 30, 2021	Mar. 31, 2024
Reverse Recapitalization [Line Items]
Number of warrants issued		26,724,000
Concord III | Private placement warrants
Reverse Recapitalization [Line Items]
Number of warrants issued	9,400,000
Concord III | Public warrants
Reverse Recapitalization [Line Items]
Number of warrants issued	17,250,000
Legacy G C T | Private placement and public warrants | Sponsor
Reverse Recapitalization [Line Items]
Number of warrants vested and retained	4,492,650
Number of warrants reallocated to others	2,087,350
Number of warrants forfeited	2,820,000

Reverse Recapitalization - Lega

Reverse Recapitalization - Legacy GCT and Sponsor Earn out Shares (Details) - Legacy G C T $ / shares in Units, $ in Millions	Mar. 26, 2024 USD ($) $ / shares shares
Earnout shares
Reverse Recapitalization [Line Items]
Number of shares issued	20,000,000
Threshold trading days calculated for issuing shares	60 days
Fair value of shares issued | $	$ 108.8
Impact on stockholder's equity | $	$ 0
Earnout shares | VWAP of the Company's common stock equals or exceeds $12.50 per share
Reverse Recapitalization [Line Items]
Number of shares issued	6,666,667
Threshold trading days calculated for issuing shares	20 days
Consecutive threshold trading days calculated for issuing shares	30 days
Threshold VWAP of stock to trigger earn out shares | $ / shares	$ 12.50
Earnout shares | VWAP of the Company's common stock equals or exceeds $15.00 per share
Reverse Recapitalization [Line Items]
Number of shares issued	6,666,666
Threshold trading days calculated for issuing shares	20 days
Consecutive threshold trading days calculated for issuing shares	30 days
Threshold VWAP of stock to trigger earn out shares | $ / shares	$ 15
Earnout shares | VWAP of the Company's common stock equals or exceeds $17.50 per share
Reverse Recapitalization [Line Items]
Number of shares issued	6,666,667
Threshold trading days calculated for issuing shares	20 days
Consecutive threshold trading days calculated for issuing shares	30 days
Threshold VWAP of stock to trigger earn out shares | $ / shares	$ 17.50
Sponsor Earnout Shares
Reverse Recapitalization [Line Items]
Number of shares issued	1,920,375
Threshold trading days calculated for issuing shares	6 months
Fair value of shares issued | $	$ 10.4
Impact on stockholder's equity | $	$ 0
Sponsor Earnout Shares | Minimum
Reverse Recapitalization [Line Items]
Number of shares issued	570,796
Sponsor Earnout Shares | VWAP of the Company's common stock equals or exceeds $12.50 per share
Reverse Recapitalization [Line Items]
Number of shares issued	640,125
Threshold trading days calculated for issuing shares	20 days
Consecutive threshold trading days calculated for issuing shares	30 days
Threshold VWAP of stock to trigger earn out shares | $ / shares	$ 12.50
Sponsor Earnout Shares | VWAP of the Company's common stock equals or exceeds $15.00 per share
Reverse Recapitalization [Line Items]
Number of shares issued	640,125
Threshold trading days calculated for issuing shares	20 days
Consecutive threshold trading days calculated for issuing shares	30 days
Threshold VWAP of stock to trigger earn out shares | $ / shares	$ 15
Sponsor Earnout Shares | VWAP of the Company's common stock equals or exceeds $17.50 per share
Reverse Recapitalization [Line Items]
Number of shares issued	640,125
Threshold trading days calculated for issuing shares	20 days
Consecutive threshold trading days calculated for issuing shares	30 days
Threshold VWAP of stock to trigger earn out shares | $ / shares	$ 17.50

Disaggregation of Revenue - Rev

Disaggregation of Revenue - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue
Revenues from contracts with customers	$ 3,265	$ 3,062
At a point in time
Disaggregation of Revenue
Revenues from contracts with customers	2,378	599
Over time
Disaggregation of Revenue
Revenues from contracts with customers	887	2,463
Product Revenues
Disaggregation of Revenue
Revenues from contracts with customers	2,378	599
Product Revenues | At a point in time
Disaggregation of Revenue
Revenues from contracts with customers	2,378	599
Service Revenues
Disaggregation of Revenue
Revenues from contracts with customers	887	2,463
Service Revenues | Over time
Disaggregation of Revenue
Revenues from contracts with customers	$ 887	$ 2,463

Disaggregation of Revenue - Net

Disaggregation of Revenue - Net revenues categorized by customer location (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue
Revenues from contracts with customers	$ 3,265	$ 3,062
Korea
Disaggregation of Revenue
Revenues from contracts with customers	2,000
Germany
Disaggregation of Revenue
Revenues from contracts with customers	796
United States
Disaggregation of Revenue
Revenues from contracts with customers	389	1,968
China
Disaggregation of Revenue
Revenues from contracts with customers	$ 80	$ 1,094

Disaggregation of Revenue - Con

Disaggregation of Revenue - Contract assets and liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue
Contract assets	$ 4,313	$ 3,439
Assets recognized for costs incurred to fulfill a contract (*)	13	12
Contract liabilities	35	48
Revenues recognized that were included in the contract liabilities	$ 12	$ 650

Fair Value of Measurements (Det

Fair Value of Measurements (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value of Measurements
Convertible promissory notes	$ 10,317	$ 34,033
Warrant liabilities	10,584
Level 3
Fair Value of Measurements
Convertible promissory notes	10,317	$ 34,033
Warrant liabilities	$ 10,584

Fair Value of Measurements - Va

Fair Value of Measurements - Valuation techniques and the inputs (Details) $ in Thousands	Mar. 31, 2024 USD ($) $ / shares Y	Dec. 31, 2023 USD ($)
Binomial Lattice Model ("BLM") | Exercise price | Public warrants
Fair Value of Measurements
Warrant liabilities, measurement input | $ / shares	11.50
Binomial Lattice Model ("BLM") | Term to expiration | Public warrants
Fair Value of Measurements
Warrant liabilities, measurement input | Y	5
Black Scholes Merton Model ("BSM") or BLM | Exercise price | Private placement warrants
Fair Value of Measurements
Warrant liabilities, measurement input | $ / shares	11.50
Black Scholes Merton Model ("BSM") or BLM | Term to expiration | Private placement warrants
Fair Value of Measurements
Warrant liabilities, measurement input | Y	5
Black Scholes Merton Model ("BSM") or BLM | Volatility | Private placement warrants
Fair Value of Measurements
Warrant liabilities, measurement input	0.194
Black Scholes Merton Model ("BSM") or BLM | Risk-free rate | Private placement warrants
Fair Value of Measurements
Warrant liabilities, measurement input	0.042
Convertible promissory notes, current | Discounted Cash Flow Model ("DCF") | Level 3
Fair Value of Measurements
Fair value | $	$ 5,645
Convertible promissory notes, current | Discounted Cash Flow Model ("DCF") | Discount factor
Fair Value of Measurements
Convertible promissory notes, measurement input	0.102
Convertible promissory notes, current | Discounted Cash Flow Model ("DCF") | Remaining term
Fair Value of Measurements
Convertible promissory notes, measurement input | Y	0.25
Convertible promissory notes, current | PWERM | Level 3
Fair Value of Measurements
Fair value | $		$ 27,794
Convertible promissory notes, net of current | PWERM | Level 3
Fair Value of Measurements
Fair value | $		$ 6,239
Convertible promissory notes, net of current | Binomial Lattice Model ("BLM") | Level 3
Fair Value of Measurements
Fair value | $	$ 4,672
Convertible promissory notes, net of current | Binomial Lattice Model ("BLM") | Stock price
Fair Value of Measurements
Convertible promissory notes, measurement input | $ / shares	6.58
Convertible promissory notes, net of current | Binomial Lattice Model ("BLM") | Remaining term
Fair Value of Measurements
Convertible promissory notes, measurement input | Y	1.9
Convertible promissory notes, net of current | Binomial Lattice Model ("BLM") | Credit spread
Fair Value of Measurements
Convertible promissory notes, measurement input	0.050
Convertible promissory notes, net of current | Binomial Lattice Model ("BLM") | Volatility
Fair Value of Measurements
Convertible promissory notes, measurement input	0.322
Convertible promissory notes, net of current | Binomial Lattice Model ("BLM") | Risk-free rate
Fair Value of Measurements
Convertible promissory notes, measurement input	0.046
Warrant liabilities - private and public warrants | Black Scholes Merton Model ("BSM") or BLM | Level 3
Fair Value of Measurements
Fair value | $	$ 9,150
Warrant liabilities - other | Level 3
Fair Value of Measurements
Fair value | $	$ 1,434
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Exercise price | Minimum
Fair Value of Measurements
Warrant liabilities, measurement input | $ / shares	5
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Exercise price | Weighted average
Fair Value of Measurements
Warrant liabilities, measurement input | $ / shares	10
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Exercise price | Maximum
Fair Value of Measurements
Warrant liabilities, measurement input | $ / shares	18.75
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Term to expiration | Minimum
Fair Value of Measurements
Warrant liabilities, measurement input | Y	0.4
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Term to expiration | Maximum
Fair Value of Measurements
Warrant liabilities, measurement input | Y	2.6
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Volatility | Minimum
Fair Value of Measurements
Warrant liabilities, measurement input	0.295
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Volatility | Maximum
Fair Value of Measurements
Warrant liabilities, measurement input	0.327
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Risk-free rate | Minimum
Fair Value of Measurements
Warrant liabilities, measurement input	0.044
Warrant liabilities - other | Black Scholes Merton Model ("BSM") or BLM | Risk-free rate | Maximum
Fair Value of Measurements
Warrant liabilities, measurement input	0.054

Fair Value of Measurements - Ch

Fair Value of Measurements - Changes in the fair value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Fair Value of Measurements
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other (expenses) income, net	Other (expenses) income, net
Convertible promissory notes
Fair Value of Measurements
Fair value as of beginning of period	$ 34,033	$ 31,166
Change in fair value	1,203	(549)
Conversion	(41,209)
Borrowing	16,290
Fair value as of end of period	10,317	$ 30,617
Warrant liabilities
Fair Value of Measurements
Assumed at closing	5,958
Change in fair value	4,626
Fair value as of end of period	$ 10,584

Balance Sheet Components - Inve

Balance Sheet Components - Inventory (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Inventory
Raw materials	$ 414		$ 448
Work-in-process	498		601
Finished goods	872		437
Total inventory	1,784		$ 1,486
Write-downs of inventory	$ 0	$ 0

Balance Sheet Components - Prep

Balance Sheet Components - Prepaid expenses and other assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Balance Sheet Components
Prepaid expenses	$ 3,345	$ 433
Prepaid inventory	1,429	279
Lease deposit	413	434
Other receivables and current assets	279	117
IPO expenses		(1,643)
Prepaid expenses and other current assets	$ 5,466	$ 2,906

Balance Sheet Components - Accr

Balance Sheet Components - Accrued and other current liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Balance Sheet Components
Payroll and related expenses	$ 9,830	$ 9,880
Accrued payables	7,853	6,319
Other taxes payable	3,399	158
Current portion of interest payable	3,395	6,915
Professional fees	444	499
Royalty and license fee	60	58
Product warranty	64	55
Other	107	72
Accrued and other current liabilities	$ 25,152	$ 23,956

Debt - Outstanding debt (Detail

Debt - Outstanding debt (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Borrowings
Borrowings	$ 50,470	$ 79,856
Fair Value	50,157	78,542
Less: current portion	(45,485)	(72,303)
Debt, net of current portion	4,672	6,239
Historical convertible promissory notes
Borrowings
Borrowings	5,630	35,347
Fair Value	5,645	34,033
2023 & 2024 convertible promissory notes
Borrowings
Borrowings	5,000
Fair Value	4,672
Borrowings
Borrowings
Borrowings	39,840
Borrowings | KEB Hana Bank
Borrowings
Borrowings	6,682	6,980
Fair Value	6,682	6,980
Borrowings | IBK Industrial Bank
Borrowings
Borrowings	6,831	7,135
Fair Value	6,831	7,135
Borrowings | Note payable (one individual investor)
Borrowings
Borrowings	1,000	1,000
Fair Value	1,000	1,000
Borrowings | M-Venture Investment, Inc.
Borrowings
Borrowings	7,425	7,756
Fair Value	7,425	7,756
Borrowings | Anapass, Inc, related party
Borrowings
Borrowings	9,653	10,082
Fair Value	9,653	10,082
Borrowings | i Best Investment Co., Ltd
Borrowings
Borrowings	7,425	10,082
Fair Value	7,425	10,082
Borrowings | Kyeongho Lee
Borrowings
Borrowings	824	1,474
Fair Value	$ 824	$ 1,474

Debt - Expected future minimum

Debt - Expected future minimum principal payments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Borrowings
2024, remainder	$ 45,470
2025	0
2026	5,000
Total	50,470	$ 79,856
Convertible Notes
Borrowings
2024, remainder	5,630
2025	0
2026	5,000
Total	10,630
Borrowings
Borrowings
2024, remainder	39,840
2025	0
Total	$ 39,840

Debt - Convertible Promissory N

Debt - Convertible Promissory Notes (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) item $ / shares shares	Feb. 29, 2024 USD ($)	Dec. 31, 2023 USD ($)
Borrowings
Amount outstanding	$ 50,470		$ 79,856
Historical convertible promissory notes
Borrowings
Amount of debt converted	$ 32,100
Number of shares issued on conversion of debt | shares	4,258,223
Amount of principal and interest outstanding	$ 7,900
Number of noteholders | item	2
Conversion price | $ / shares	$ 3.50
Amount outstanding	$ 5,630		$ 35,347
Historical convertible promissory notes | Minimum
Borrowings
Interest rate (as a percent)	4%
Historical convertible promissory notes | Maximum
Borrowings
Interest rate (as a percent)	7%
2023 & 2024 convertible promissory notes
Borrowings
Amount outstanding	$ 5,000
2023 & 2024 convertible promissory notes | CVT Investors
Borrowings
Principal amount	$ 13,300
Interest rate (as a percent)	5%
Amount of debt converted	$ 13,400
Number of shares issued on conversion of debt | shares	2,004,535
Conversion price | $ / shares	$ 6.67
Amount outstanding	$ 0
2023 & 2024 convertible promissory notes | Strategic investor
Borrowings
Principal amount	$ 5,000	$ 5,000
Interest rate (as a percent)	5%
Term for conversion	6 months
Conversion price | $ / shares	$ 10

Debt - Borrowings Pursuant to T

Debt - Borrowings Pursuant to Term Loan and Security Agreements (Details) ₩ in Millions

1 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2023 USD ($)

Jul. 31, 2016 USD ($)

Mar. 31, 2024 USD ($)

Dec. 31, 2021 USD ($)

Dec. 31, 2021 KRW (₩)

Dec. 31, 2022 USD ($)

Dec. 31, 2022 KRW (₩)

Dec. 31, 2017 USD ($)

Dec. 31, 2023 KRW (₩)

Dec. 31, 2022 KRW (₩)

Sep. 30, 2022 USD ($)

Sep. 30, 2022 KRW (₩)

May 31, 2022 USD ($)

May 31, 2022 KRW (₩)

Apr. 30, 2022 USD ($)

Apr. 30, 2022 KRW (₩)

Dec. 31, 2021 KRW (₩)

Oct. 31, 2021 USD ($)

Oct. 31, 2021 KRW (₩)

Jun. 30, 2021 USD ($)

Dec. 31, 2019

Dec. 31, 2017 KRW (₩)

Jan. 31, 2017 USD ($)

Jan. 31, 2017 KRW (₩)

Jul. 31, 2016 KRW (₩)

Borrowings

Amount outstanding

$ 79,856,000

$ 50,470,000

Borrowings

Borrowings

Amount outstanding

$ 39,840,000

KEB Hana Bank | Borrowings

Borrowings

Principal amount

$ 6,700,000,000

₩ 9,000

Annual interest rate

2.60%

5.20%

Additional extension term (in years)

1 year

Amount outstanding

6,980,000

$ 6,682,000

IBK Industrial Bank | Borrowings

Borrowings

Principal amount

$ 6,800,000

₩ 9,200

Interest rate (as a percent)

4.90%

Amount outstanding

7,135,000

$ 6,831,000

Note payable (one individual investor) | Borrowings

Borrowings

Principal amount

$ 1,000,000

Interest rate (as a percent)

4%

Amount of principal and interest outstanding

$ 1,100,000

Amount outstanding

1,000,000

1,000,000

M-Venture Investment, Inc. | Borrowings

Borrowings

Amount outstanding

7,756,000

$ 7,425,000

M-Venture Investment, Inc. | Term loan and security agreement, one

Borrowings

Principal amount

$ 3,700,000

₩ 5,000

Interest rate (as a percent)

6.50%

Amount outstanding

$ 3,100,000

$ 3,000,000

₩ 4,000

Amount repaid

$ 400,000

₩ 600

300,000

₩ 0.4

M-Venture Investment, Inc. | Term loan and security agreement, two

Borrowings

Amount outstanding

$ 4,800,000

M-Venture Investment, Inc. | Term loan and security agreement, two, draw one

Borrowings

Principal amount

$ 700,000

₩ 1,000

Interest rate (as a percent)

6.50%

M-Venture Investment, Inc. | Term loan and security agreement, two, draw two

Borrowings

Principal amount

$ 3,700,000

₩ 5,000

Interest rate (as a percent)

8.70%

Anapass, Inc, related party | Borrowings

Borrowings

Amount outstanding

10,082,000

$ 9,653,000

Anapass, Inc, related party | Term loan and security agreement, one

Borrowings

Principal amount

$ 4,500,000

₩ 6,000

Interest rate (as a percent)

5.50%

5.50%

Amount outstanding

$ 4,500,000

Anapass, Inc, related party | Term loan and security agreement, two

Borrowings

Interest rate (as a percent)

5.50%

Amount outstanding

$ 5,200,000

Anapass, Inc, related party | Term loan and security agreement, two, draw one

Borrowings

Principal amount

$ 2,200,000

₩ 3,000

Anapass, Inc, related party | Term loan and security agreement, two, draw two

Borrowings

Principal amount

$ 3,000,000

₩ 4,000

i Best Investment Co., Ltd | Borrowings

Borrowings

Principal amount

$ 10,300,000

$ 10,300,000

₩ 14,000

₩ 14,000

Interest rate (as a percent)

6.50%

6.50%

6.50%

6.50%

Amount outstanding

$ 10,082,000

7,425,000

i Best Investment Co., Ltd | Term loan and security agreement, draw one

Borrowings

Amount outstanding

3,300,000

i Best Investment Co., Ltd | Term loan and security agreement, draw two

Borrowings

Amount repaid

800,000

i Best Investment Co., Ltd | Term loan and security agreement, draw three

Borrowings

Amount outstanding

1,600,000

i Best Investment Co., Ltd | Term loan and security agreement, draw four

Borrowings

Amount repaid

2,300,000

i Best Investment Co., Ltd | Term loan and security agreement, draw five

Borrowings

Amount outstanding

2,300,000

i Best Investment Co., Ltd | Term loan and security agreement, draw six

Borrowings

Amount outstanding

800,000

Kyeongho Lee | Borrowings

Borrowings

Amount outstanding

$ 1,474,000

824,000

Kyeongho Lee | Promissory notes

Borrowings

Principal amount

400,000

$ 400,000

₩ 500,000

₩ 500,000

Amount outstanding

$ 700,000

Kyeongho Lee | Promissory notes | Minimum

Borrowings

Interest rate (as a percent)

9%

9%

9%

Kyeongho Lee | Promissory notes | Maximum

Borrowings

Interest rate (as a percent)

7.50%

7.50%

7.50%

Kyeongho Lee | Term loans

Borrowings

Principal amount

$ 100,000

$ 700,000

₩ 110,000

₩ 1,000

Interest rate (as a percent)

0%

Amount outstanding

$ 82,000

Commitments and Contingencies -

Commitments and Contingencies - Purchase Commitment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Feb. 29, 2024	Dec. 31, 2023
Purchase Commitment
Research and development expense	$ 5,521	$ 902
Unpaid recorded expenses included in accounts payable	1,242			$ 17,814
Research and development agreement with Samsung
Purchase Commitment
Outstanding purchase commitments	0
Total fee amount	21,100
Fee amount to be paid over development milestones	11,700
Additional NRE to be paid as fee amount	$ 9,400
Period for payment of additional NRE	4 years
Gain on release of unconditional liability	$ 14,600
Research And Development Agreement With Alpha Holdings Co., Ltd
Purchase Commitment
Total fee amount			$ 7,600
Research and development expense	3,500
Aggregated unpaid amount	$ 5,000

Commitments and Contingencies_2

Commitments and Contingencies - Assets Pledged as Collateral (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Borrowings
Borrowings	$ 50,470	$ 79,856
Cash and cash equivalents	16,122	258
Accounts receivable	5,103	4,920
Inventory	1,784	1,486
Property and equipment	644	772
KEB Hana Bank | Related party | Assets pledged as collateral | Borrowings
Borrowings
Borrowings	6,700	7,000
IBK Industrial Bank | Related party | Assets pledged as collateral | Borrowings
Borrowings
Borrowings	6,800	7,100
Anapass, Inc. | Related party | Assets pledged as collateral | Borrowings
Borrowings
Borrowings	9,700	10,100
Cash and cash equivalents	16,122	254
Accounts receivable	5,118	4,920
Inventory	1,784	1,486
Property and equipment	1,988	352
Intangible assets and others	$ 187	$ 199

Common Stock (Details)

Common Stock (Details) - shares	Mar. 31, 2024	Dec. 31, 2023
Common Stock
Total shares Authorized	440,000,000
Common stock, shares authorized	400,000,000	200,000,000
Preferred Stock, Shares Authorized	40,000,000	82,352,000

Common Stock - Shares authorize

Common Stock - Shares authorized (Details) - shares shares in Thousands	Mar. 31, 2024	Dec. 31, 2023
Common Stock
Shares of authorized but unissued common stock	33,167	5,902
Warrants
Common Stock
Shares of authorized but unissued common stock	26,724	2,894
Shares available for future grant from 2024 plan
Common Stock
Shares of authorized but unissued common stock	3,983
Convertible promissory notes
Common Stock
Shares of authorized but unissued common stock	800	1,835
Options issued and outstanding
Common Stock
Shares of authorized but unissued common stock	668	668
Shares available for future grant from 2024 ESPP
Common Stock
Shares of authorized but unissued common stock	600
RSUs outstanding
Common Stock
Shares of authorized but unissued common stock	392	392
Shares available for future grant from 2011 plan
Common Stock
Shares of authorized but unissued common stock		113

Warrants (Details)

Warrants (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Warrants
Number of warrants issued | shares	26,724
Warrants expiration term	3 years
August 2021
Warrants
Number of warrants issued | shares	299
August 2021 | Maximum
Warrants
Exercise price of warrants	$ 18.75
August 2021 | Minimum
Warrants
Exercise price of warrants	$ 10
September 2021
Warrants
Number of warrants issued | shares	300
Exercise price of warrants	$ 5
February 2023 ~ June 2023
Warrants
Number of warrants issued | shares	2,115
February 2023 ~ June 2023 | Maximum
Warrants
Exercise price of warrants	$ 18.75
February 2023 ~ June 2023 | Minimum
Warrants
Exercise price of warrants	$ 10
July 2023
Warrants
Number of warrants issued | shares	80
Exercise price of warrants	$ 10
October 2023
Warrants
Number of warrants issued | shares	100
Exercise price of warrants	$ 10
:Public And Private Placement Warrants [Member]
Warrants
Number of warrants issued | shares	23,830
Exercise price of warrants	$ 11.50

Stock-Based Compensation (Detai

Stock-Based Compensation (Details)	Mar. 31, 2024 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Additional shares of common stock reserved for issuance	90,000
2024 Incentive Compensation Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares of common stock reserved for issuance	3,983,334

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock option activities (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended	15 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2024
Number of Stock Options Outstanding
Balances as of beginning	392
Reverse recapitalization		(1,708)
Balances as of end	392	392	392
Weighted-Average Exercise Price
Balances as of beginning (in dollars per share)	$ 6.16
Reverse recapitalization (in dollars per share)		5.01
Balances as of end (in dollars per share)	$ 6.16	$ 6.16	$ 6.16
Employee Stock Option
Shares Available for Grant
Options granted			0
Number of Stock Options Outstanding
Balances as of beginning	3,579
Granted			0
Balances as of end	668	3,579	668
Vested as of end	667		667
Vested and expected to be vest as of end	634		634
Weighted-Average Exercise Price
Balances as of beginning (in dollars per share)	$ 0.02
Balances as of end (in dollars per share)	0.11	$ 0.02	$ 0.11
Vested as of end (in dollars per share)	0.11		0.11
Vested and expected to be vest as of end (in dollars per share)	$ 0.11		$ 0.11
Weighted Average Remaining Contractual Life (Years)
Options Outstanding Weighted Average Remaining Contractual Life	5 years 3 months 18 days	5 years 6 months
Vested as of December 31, 2023	5 years 3 months 18 days
Vested and expected to be vest as of December 31, 2023	5 years 1 month 6 days
Balance as if beginning Aggregated Intrinsic Value	$ 5,543	$ 4,405	$ 5,543
Vested as of Aggregated Intrinsic Value	5,532		5,532
Exercisable as of Aggregated Intrinsic Value	$ 5,256		$ 5,256
Employee Stock Option | Retrospectively adjusted
Number of Stock Options Outstanding
Balances as of beginning	668
Reverse recapitalization		(2,911)
Balances as of end		668
Weighted-Average Exercise Price
Balances as of beginning (in dollars per share)	$ 0.11
Reverse recapitalization (in dollars per share)		0.09
Balances as of end (in dollars per share)		$ 0.11
Weighted Average Remaining Contractual Life (Years)
Options Outstanding Weighted Average Remaining Contractual Life		5 years 6 months
Balance as if beginning Aggregated Intrinsic Value		$ 4,405
RSUs
Number of Stock Options Outstanding
Balances as of beginning	2,100
Balances as of end		2,100
Weighted-Average Exercise Price
Balances as of beginning (in dollars per share)	$ 1.15
Balances as of end (in dollars per share)		$ 1.15

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
The Company and Summary of Significant Accounting Policies
stock-based compensation	$ 0.9
RSUs
The Company and Summary of Significant Accounting Policies
Unrecognized compensation cost related to RSUs	$ 2.1
Expected weighted average period for recognition of unrecognized compensation cost related to RSUs	3 years 8 months 12 days
stock-based compensation	$ 0.3

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Taxes
Income tax expense	$ 59,000	$ 50,000
Effective tax rate	7.20%	3.70%
Unrecognized tax benefits	$ 3,100,000
Unrecognized tax benefits effective tax rate	1,700,000
Interest expense or penalties related to unrecognized tax benefits	$ 0

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the unrecognized tax benefits (Details) $ in Millions	Mar. 31, 2024 USD ($)
Income Taxes
Amount of unrecognized tax benefits that, if recognized, would affect effective tax rate	$ 1.7

Employee Benefit Plans - Net li

Employee Benefit Plans - Net liability for severance payments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Employee Benefit Plans
Liability for severance payments, beginning	$ 7,764	$ 7,997
Deposit	(276)	(308)
Liability for severance payments, ending	$ 7,488	$ 7,689

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Related Party Transactions
Other	$ 107		$ 72
Interest expense	2,082	$ 935
Related party | Anapass
Related Party Transactions
Borrowings	9,653		10,082
Other	106		212
Interest expense	100	100
Related party | Kyeongho Lee
Related Party Transactions
Borrowings	824		1,474
Other	87		$ 182
Interest expense	$ 22,000	$ 26,000

Segments and Information (Detai

Segments and Information (Details)	3 Months Ended
	Mar. 31, 2024 segment
Segments and Information
Number of operating segment	1

Segments and Information - Long

Segments and Information - Long-lived assets by geographic region (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Segments and Geographical Information
Total long-lived assets	$ 1,987	$ 2,293
United States
Segments and Geographical Information
Total long-lived assets	817	930
Korea
Segments and Geographical Information
Total long-lived assets	$ 1,170	$ 1,363

Net Income (Loss) Per Share - C

Net Income (Loss) Per Share - Computation of basic and diluted net loss per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Numerator:
Net income (loss), basic		$ 757	$ (1,393)
Net income (loss), diluted		$ 757	$ (1,393)
Denominator:
Weighted-average common shares outstanding, basic	[1]	25,468	23,862
Add: effect of dilutive securities		789
Weighted-average common shares outstanding, diluted	[1]	26,257	23,862
Net income (loss) per share, basic and diluted
Net income (loss) per common share - basic	[1]	$ 0.03	$ (0.06)
Net income (loss) per common share - diluted	[1]	$ 0.03	$ (0.06)
[1] Amounts as of December 31, 2023 differ from those in prior year consolidated financial statements as they were retrospectively adjusted as a result of the accounting for the Business Combination (as defined in the Notes to the Unaudited Condensed Consolidated Financial Statements.)

Net Income (Loss) Per Share -_2

Net Income (Loss) Per Share - Computation of outstanding potentially dilutive common stock (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities that were excluded from the computation of diluted net loss per common share	32,267	3,689
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities that were excluded from the computation of diluted net loss per common share	26,724	995
Convertible promissory notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities that were excluded from the computation of diluted net loss per common share	5,543	1,809
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities that were excluded from the computation of diluted net loss per common share		885

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent event $ in Millions, ₩ in Billions	1 Months Ended
	May 31, 2024 shares	Apr. 30, 2024 USD ($)	Apr. 30, 2024 KRW (₩)	Apr. 30, 2024 KRW (₩)
Historical convertible promissory notes notes.
Subsequent Events
Principal amount | $		$ 0.6
Share Reserve
Subsequent Events
Maximum number of shares of Common stock | shares	3,983,334
Share Reserve | 2024 Employee Stock Purchase Plan
Subsequent Events
Reserve share | shares	600,000
M-Venture Investment, Inc.
Subsequent Events
Term loan outstanding		3		₩ 4
Principal amount of loan extended maturity date from April 2024 to June 2024		0.7		1
M-Venture Investment, Inc. | Term loans
Subsequent Events
Term loan outstanding		4.4		6
Repayment of short term loan		1.5	₩ 2
Principal amount of loan extended maturity date from April 2024 to July 2024		$ 3.7		₩ 5
B. Riley Principal Capital II, LLC
Subsequent Events
Period for issuance of stock		24 months	24 months
Common stock purchase agreement | B. Riley Principal Capital II, LLC
Subsequent Events
Maximum aggregate amount of stock issuance | $		$ 50

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 757	$ (1,393)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false