[Form 4] GCT Semiconductor Holding, Inc. Insider Trading Activity

Rhea-AI Filing Summary

GCT Semiconductor Holding director Hyunsoo Shin reported purchases of common stock on September 4-5, 2025, acquiring 8,250 shares at $1.26 and 10,300 shares at $1.30 respectively, increasing his beneficial ownership to 650,254 shares. The Form 4 was signed by an attorney-in-fact and shows direct ownership; no derivative transactions were reported.

Positive

• Director purchase: Reporting person acquired a total of 18,550 common shares, increasing direct beneficial ownership to 650,254 shares.
• Plain-vanilla transactions: All reported activity are direct common stock purchases with no derivatives or dispositions disclosed.

Negative

• None.

Insights

Financial Analyst

TL;DR: Director purchases add ~18,550 shares, modestly increasing direct stake; transaction sizes are small relative to total float.

The reported purchases on 09/04/2025 and 09/05/2025 total 18,550 common shares at prices of $1.26 and $1.30. The filing shows direct beneficial ownership of 650,254 shares after the trades. These are straightforward open-market acquisitions recorded on Form 4 with no derivatives or complex instruments disclosed. The filings do not include context on total outstanding shares, so market impact cannot be assessed from this document alone.

Corporate Governance Expert

TL;DR: Insider buying by a Class II director signals alignment with shareholders but is routine in scale based on disclosed numbers.

The purchases were reported by a director and executed as direct acquisitions, which is a conventional governance signal of insider alignment. The signature is provided by an attorney-in-fact, consistent with delegated filing practices. No sales, option exercises, or related-party transactions are disclosed. The Form 4 contains no indications of unusual timing or structured plans under Rule 10b5-1.

SEC Form 4

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
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).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Shin Hyunsoo

(Last) (First) (Middle)

C/O GCT SEMICONDUCTOR HOLDING, INC.

2290 NORTH 1ST STREET, SUITE 201

(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)

X	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Class II Director

3. Date of Earliest Transaction (Month/Day/Year)
09/04/2025

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	09/04/2025		P		8,250	A	$1.26	639,954	D
Common Stock	09/05/2025		P		10,300	A	$1.3	650,254	D

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

Explanation of Responses:

	/s/ Edmond Cheng, attorney-in-fact	09/08/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions did GCTS director Hyunsoo Shin report on Form 4?

The director reported purchases of 8,250 shares on 09/04/2025 at $1.26 and 10,300 shares on 09/05/2025 at $1.30.

How many shares does Hyunsoo Shin beneficially own after the reported trades?

After the reported transactions, Hyunsoo Shin beneficially owns 650,254 shares as shown on the Form 4.

Were any derivative securities or sales reported by the insider in this filing?

No. The Form 4 reports only non-derivative common stock acquisitions and shows no derivative transactions or dispositions.

Who signed the Form 4 filing for Hyunsoo Shin and when?

The filing was signed by Edmond Cheng, attorney-in-fact, on 09/08/2025 as indicated on the form.