FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Expires: December 31, 2014 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person * Concord Sponsor Group III LLC (Last) (First) (Middle) C/O GCT SEMICONDUCTOR HOLDING, INC. 2290 NORTH 1ST STREET (Street) SAN JOSE CA 95131 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol GCT Semiconductor Holding, Inc. [ GCTS ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 03/26/2024
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/26/2024		C (1)		1	A	(1)	7,957,727	D (2)
Common Stock	03/26/2024		J (3)		932,052	D	(3)	7,025,675	D (2)
Common Stock	03/26/2024		J (4)		729,072	D	(4)	6,296,603	D (2)
Common Stock	03/26/2024		J (5)		1,304,477	D	(5)	4,992,126 (10)	D (2)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Class B Common Stock	(6)	03/26/2024		C (1)			1	(6)	(6)	Common Stock	1	(1)	0	D (2)
Warrant	$ 11.5	03/26/2024		A (7)		8,260,606		(7)	(7)	Common Stock	8,260,606	$ 0 (7)	8,260,606	D (2)
Warrant	$ 11.5	03/26/2024		J (8)			2,478,182	(7)	(7)	Common Stock	2,478,182	$ 0 (8)	5,782,424	D (2)
Warrant	$ 11.5	03/26/2024		J (9)			1,834,338	(7)	(7)	Common Stock	1,834,338	$ 0 (9)	3,948,086	D (2)

Explanation of Responses:

1. Represents one share of common stock of the Issuer acquired upon conversion of one share of Class B common stock of the Issuer (f/k/a Concord Acquisition Corp III) upon the closing of the business combination (the "Closing") by and among the Issuer, Gibraltar Merger Sub Inc. ("Merger Sub"), a Delaware corporation, and GCT Semiconductors, Inc. ("GCT"), a Delaware corporation, pursuant to a business combination agreement entered into on November 2, 2023 (the "Business Combination Agreement"). At the Closing, Merger Sub merged with and into GCT, with GCT surviving the merger and becoming a wholly-owned direct subsidiary of the Issuer, and the Issuer was renamed to GCT Semiconductor Holding, Inc.

2. The securities are held directly by the Reporting Person. The Reporting Person is governed by a board of managers consisting of three managers, Bob Diamond, David Schamis and Jeff Tuder. Any action by the Reporting Person with respect to the issuer or the issuer's securities held by the Reporting Person, including voting and dispositive decisions, requires at least a majority vote of the managers of the board of managers. Under the so-called "rule of three", because voting and dispositive decisions are made by a majority of the managers, none of the managers is deemed to be a beneficial owner of issuer's securities held by the Reporting Person, even those in which such manager holds a pecuniary interest. Accordingly, none of the managers on the Reporting Person's board of managers is deemed to have or share beneficial ownership of the founder shares held by the Reporting Person.

3. Represents 932,052 shares of common stock of the Issuer transferred from the Reporting Person to individuals and entities for no consideration pursuant to certain non-redemption agreements entered into in connection with the Issuer's extension in May, 2023.

4. Represents 729,072 shares of common stock of the Issuer forfeited by the Reporting Person to the issuer for no consideration pursuant to certain non-redemption agreements entered into in connection with the Issuer's extension in November, 2023.

5. Represents 1,304,477 shares of common stock of the Issuer transferred from the Reporting Person to individuals and entities for no consideration pursuant to a sponsor support agreement (the "Sponsor Support Agreement") entered into concurrently with the Business Combination Agreement, by and among the Reporting Person, CA2 Co-Investment LLC, a Delaware limited liability company, the Issuer and GCT on November 2, 2023.

6. The shares of Class B common stock automatically convert into shares of Class A common stock at the time of the Issuer's initial business combination, or earlier at the option of the holder, on a one-for-one basis, subject to adjustment as set forth in the Issuer's registration statement on Form S-1 (File No. 333-254789), as amended (the "Registration Statement").

7. These warrants will become exercisable 30 days after the Closing and expire five years after the Closing, as described in the Registration Statement.

8. Represents 2,478,182 warrants of the Issuer forfeited by the Reporting Person to the Issuer for no consideration pursuant to the Sponsor Support Agreement.

9. Represents 1,834,338 warrants of the Issuer transferred from the Reporting Person to individuals and entities for no consideration pursuant to the Sponsor Support Agreement.

10. Includes 1,790,489 shares of common stock of the Issuer that are unvested and subject to vesting based on the trading price of the common stock of Issuer exceeding certain specified targets prior to March 26, 2029.

	/s/ Jason T. Simon, Attorney-in-Fact	03/28/2024
	** Signature of Reporting Person	Date
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