Sec Form 3 Filing - Hussain Naiem @ ADVENT TECHNOLOGIES HOLDINGS, INC. - 2024-02-02

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Hussain Naiem 2. Issuer Name and Ticker or Trading Symbol ADVENT TECHNOLOGIES HOLDINGS, INC. [ ADN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Financial Officer (Last) (First) (Middle) C/O ADVENT TECHNOLOGIES HOLDINGS, INC., 500 RUTHERFORD AVENUE SUITE 102 3. Date of Earliest Transaction (MM/DD/YY) 02/02/2024 (Street) BOSTON, MA02129 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 85,000 ( 1 ) 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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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 Employee Stock Options (right to buy) ( 2 ) $ 2.74 03/18/2022( 3 ) 03/18/2032 Common Stock 40,000 D Employee Stock Options (right to buy) ( 2 ) $ 2.94 07/12/2023( 4 ) 07/12/2033 Common Stock 45,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Hussain Naiem C/O ADVENT TECHNOLOGIES HOLDINGS, INC. 500 RUTHERFORD AVENUE SUITE 102 BOSTON, MA02129 Chief Financial Officer Signatures /s/ Naiem Hussain 02/12/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Includes 45,000 restricted stock units ("RSUs") granted July 12, 2022, and 40,000 RSUs granted March 18, 2022, each representing a contingent right to receive common stock. Such RSUs were granted pursuant to Issuer's 2021 Equity Incentive Plan, dated February 4, 2021 (the "Plan"). RSUs are a common stock equivalent that may be settled solely by delivery of an equal number of shares of Issuer's common stock. These RSUs vest 25% on each anniversary of their grant date over four years. ( 2 )Employee stock options (right to buy) ("Options") granted pursuant to the Plan. ( 3 )Options vest 25% per year over four years on each anniversary of the grant date and will be fully vested as of March 18, 2025. ( 4 )Options vest 25% per year over four years on each anniversary of the grant date and will be fully vested as of July 12, 2026.

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).

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