Chun Kukjin

SEC source: 0000929638-26-003834 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 111,607

F1 · shares: Each Restricted Stock Unit ("RSU") represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of GCT Semiconductor Holding, Inc. (the "Issuer") following vesting. The RSUs become payable in Common Stock in accordance with a deferral election made by the reporting person.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2026 through March 31, 2027 (beginning with the quarter ending June 30, 2026) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $2.12 on September 30, 2026, rounded down to the nearest whole share.

F3 · shares: The RSUs will vest on March 31, 2027, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-26-002494 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 98,636

F1 · shares: Each Restricted Stock Unit ("RSU") represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of GCT Semiconductor Holding, Inc. (the "Issuer") following vesting. The RSUs become payable in Common Stock in accordance with a deferral election made by the reporting person.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2026 through March 31, 2027 (beginning with the quarter ending June 30, 2026) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $2.97 on June 30, 2026, rounded down to the nearest whole share.

F3 · shares: The RSUs will vest on March 31, 2027, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-26-001358 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 89,377

F1 · shares: Each Restricted Stock Unit ("RSU") represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of GCT Semiconductor Holding, Inc. (the "Issuer") following vesting. The RSUs become payable in Common Stock in accordance with a deferral election made by the reporting person.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2025 through March 31, 2026 (beginning with the quarter ending June 30, 2025) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $1.14 on March 31, 2026, rounded down to the nearest whole share.

F3 · shares: The RSUs will vest on March 31, 2026, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-26-000929 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 65,255

SEC source: 0000929638-26-000018 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 105,255

F1 · shares: Each Restricted Stock Unit ("RSU") represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of GCT Semiconductor Holding, Inc. (the "Issuer") following vesting. The RSUs become payable in Common Stock in accordance with a deferral election made by the reporting person.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2025 through March 31, 2026 (beginning with the quarter ending June 30, 2025) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $1.20 on December 31, 2025, rounded down to the nearest whole share.

F3 · shares: The RSUs will vest on March 31, 2026, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-25-003730 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 82,339

F1 · shares: Each Restricted Stock Unit ("RSU") represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of GCT Semiconductor Holding, Inc. (the "Issuer") following vesting. The RSUs become payable in Common Stock in accordance with a deferral election made by the reporting person.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2025 through March 31, 2026 (beginning with the quarter ending June 30, 2025) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $1.52 on September 30, 2025, rounded down to the nearest whole share.

F3 · shares: The RSUs will vest on March 31, 2026, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-25-002495 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 64,247

F1 · shares: Each Restricted Stock Unit ("RSU") represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of GCT Semiconductor Holding, Inc. (the "Issuer") following vesting. The RSUs become payable in Common Stock in accordance with a deferral election made by the reporting person.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2025 through March 31, 2026 (beginning with the quarter ending June 30, 2025) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $1.49 on June 30, 2025, rounded down to the nearest whole share.

F3 · shares: The RSUs will vest on March 31, 2026, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-25-001448 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 45,791

F1 · shares: Represents Restricted Stock Units ("RSUs") acquired pursuant to the terms of the GCT Semiconductor Holding, Inc. (the "Issuer") GCT 2024 Omnibus Incentive Compensation Plan. Each RSU represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of the Issuer following vesting.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2024 through March 31, 2025 (beginning with the quarter ending June 30, 2024) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $1.64 on March 31, 2025, rounded down to the nearest whole share.

F3 · shares: The RSU's will vest on March 31, 2025, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-25-000006 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 28,964

F1 · shares: Represents Restricted Stock Units ("RSUs") acquired pursuant to the terms of the GCT Semiconductor Holding, Inc. (the "Issuer") GCT 2024 Omnibus Incentive Compensation Plan. Each RSU represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of the Issuer following vesting.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2024 through March 31, 2025 (beginning with the quarter ending June 30, 2024) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $2.33 on December 31, 2024, rounded down to the nearest whole share.

F3 · shares: The RSU's will vest on March 31, 2025, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-24-004021 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,162

F1 · shares: Represents Restricted Stock Units ("RSUs") acquired pursuant to the terms of the GCT Semiconductor Holding, Inc. (the "Issuer") GCT 2024 Omnibus Incentive Compensation Plan. Each RSU represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of the Issuer following vesting.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2024 through March 31, 2025 (beginning with the quarter ending June 30, 2024) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $3.35 on September 30, 2024, rounded down to the nearest whole share.

F3 · shares: The RSU's will vest on March 31, 2025, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-24-002413 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,954

F1 · shares: Represents Restricted Stock Units ("RSUs") acquired pursuant to the terms of the GCT Semiconductor Holding, Inc. (the "Issuer") GCT 2024 Omnibus Incentive Compensation Plan. Each RSU represents the right to receive one share of common stock, par value $0.0001 per share ("Common Stock") of the Issuer following vesting.

F2 · shares: The number of shares subject to and issuable under the award is determined on the last day of each calendar quarter during the period April 1, 2024 through March 31, 2025 (beginning with the quarter ending June 30, 2024) by dividing $27,500 by the fair market value per share of Common Stock, which was determined to be $5.21 on June 28, 2024, rounded down to the nearest whole share.

F3 · shares: The RSU's will vest on March 31, 2025, subject to continued service through such date.

F4 · shares: No expiration date is applicable to restricted stock units.

SEC source: 0000929638-24-001254 · form4.xml · derivative · entry 2

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,536

Underlying: Common Stock · 6,536 shares

Expires 2032-03-22

F2 · kind: Pursuant to the Business Combination Agreement, at the Effective Time, each outstanding option to purchase shares of GCT common stock was assumed and converted into an option to purchase shares of common stock of the Issuer with the same terms and conditions as were applicable to such option immediately prior to the Effective Time, subject to the applicable exchange ratio.

F3 · derivative.exercise_date: The option vests with respect to (i) twenty-five percent (25%) of the shares upon completion of one (1) year of service measured from March 22, 2022 and (ii) the balance of the shares subject to the option in a series of thirty-six (36) successive equal monthly installments upon completion of each additional month of service over the thirty-six (36) month period measured from March 22, 2023.

SEC source: 0000929638-24-001254 · form4.xml · nonDerivative · entry 1

Chun Kukjin · CIK 0002007838 · Director · Class I Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,735

F1 · kind: Pursuant to the Business Combination Agreement, dated as of November 2, 2023 (the "Business Combination Agreement"), by and among Concord Acquisition Corp III, Gibraltar Merger Sub Inc., and GCT Semiconductor, Inc. ("GCT"), at the Effective Time (as defined in the Business Combination Agreement), each award of restricted stock units relating to a share of GCT common stock granted under GCT's existing equity plans was automatically converted into an award of restricted stock units covering the number of shares of the common stock of the Issuer in the manner set forth in the Business Combination Agreement. The shares subject to RSUs reported herein will vest in equal annual installments over a four (4) year period measured from December 11, 2023.