| Item 1. | |
| (a) | Name of issuer:
GCT Semiconductor Holding, Inc. |
| (b) | Address of issuer's principal executive offices:
2290 NORTH 1ST STREET, SUITE 201, SAN JOSE, California, 95131 |
| Item 2. | |
| (a) | Name of person filing:
See response to 2(c) |
| (b) | Address or principal business office or, if none, residence:
See response to 2(c) |
| (c) | Citizenship:
This statement is filed on behalf of:
SUNP Corporation
6F, Cheongpung Building, 14, Teheran-ro 82-gil, Gangnam-gu, Seoul, 06178, Republic of Korea |
| (d) | Title of class of securities:
Common Stock, par value $0.0001 per share |
| (e) | CUSIP No.:
36170N107 |
| Item 3. | If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a: |
| (a) |  Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
|
| (b) | Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
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| (c) | Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
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| (d) | Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
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| (e) | An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
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| (f) | An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
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| (g) | A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
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| (h) | A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
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| (i) | A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
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| (j) |  A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
|
| (k) | Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
|
| | Corporation. |
| Item 4. | Ownership |
| (a) | Amount beneficially owned:
2,910,870 shares |
| (b) | Percent of class:
5.2%. The percentage ownership was calculated based upon 55,859,904 shares of the Issuer's common stock outstanding as of August 7, 2025, as reported in the Issuer's Form 10-Q filed with the SEC on August 12, 2025. |
| (c) | Number of shares as to which the person has:
|
| | (i) Sole power to vote or to direct the vote:
2,605,109 shares
|
| | (ii) Shared power to vote or to direct the vote:
305,761 shares
|
| | (iii) Sole power to dispose or to direct the disposition of:
2,605,109 shares
|
| | (iv) Shared power to dispose or to direct the disposition of:
305,761 shares
|
| Item 5. | Ownership of 5 Percent or Less of a Class. |
| | |
| Item 6. | Ownership of more than 5 Percent on Behalf of Another Person. |
| |
Not Applicable
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| Item 7. | Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person. |
| |
If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.
See Exhibit A. |
| Item 8. | Identification and Classification of Members of the Group. |
| |
Not Applicable
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| Item 9. | Notice of Dissolution of Group. |
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Not Applicable
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