Sec Form 4 Filing - Diaz Diana P @ Direct Digital Holdings, Inc. - 2025-10-16

FORM 4 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

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Diaz Diana P 2. Issuer Name and Ticker or Trading Symbol Direct Digital Holdings, Inc. [ DRCT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) CFO (Last) (First) (Middle) 1177 WEST LOOP SOUTH, SUITE 1310 3. Date of Earliest Transaction (MM/DD/YY) 10/16/2025 (Street) HOUSTON, TX77027 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 Class A Common Stock, par value $0.001 per share 10/16/2025 M 28 ( 1 ) A 65 D Class A Common Stock, par value $0.001 per share 01/24/2026 M 102 ( 3 ) A 167 D Class A Common Stock, par value $0.001 per share 01/24/2026 F 31 ( 3 ) ( 4 ) D $ 16.48 ( 3 ) 136 D Class A Common Stock, par value $0.001 per share 04/01/2026 M 33 ( 3 ) A 169 D Class A Common Stock, par value $0.001 per share 04/01/2026 F 10 ( 3 ) ( 4 ) D $ 3.34 ( 3 ) 159 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 Restricted Stock Units ( 2 ) 10/16/2025 M 28 ( 5 ) ( 5 ) ( 5 ) Class A Common Stock, par value $0.001 per share 28 ( 5 ) $ 0 28 ( 5 ) D Restricted Stock Units ( 2 ) 01/24/2026 M 102 ( 6 ) ( 6 ) ( 6 ) Class A Common Stock, par value $0.001 per share 102 ( 6 ) $ 0 0 D Employee Stock Options (right to buy) $ 3.32 ( 3 ) 03/24/2026 A 4,375 ( 3 ) ( 7 ) 03/24/2036 Class A Common Stock, par value $0.001 per share 4,375 ( 3 ) $ 0 4,375 ( 3 ) D Restricted Stock Units ( 2 ) 04/01/2026 M 33 ( 8 ) ( 8 ) ( 8 ) Class A Common Stock, par value $0.001 per share 33 ( 8 ) $ 0 68 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Diaz Diana P 1177 WEST LOOP SOUTH, SUITE 1310 HOUSTON, TX77027 CFO Signatures /s/ Mark Walker, attorney-in-fact for Diana P. Diaz 06/29/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On January 12, 2026, Direct Digital Holdings, Inc. (the "Company") effected a 55-to-1 reverse stock split (the "January Reverse Stock Split") and subsequently on April 27, 2026, the Company effected a 4-to-1 reverse stock split (the "April Reverse Stock Split," and together with the January Reverse Stock Split, the "Reverse Stock Splits"). The shares reported in connection with this transaction have been adjusted to reflect the Reverse Stock Splits. ( 2 )Restricted stock units convert into shares of the Company's Class A Common Stock, par value $0.001 per share, on a one-for-one basis. ( 3 )The shares and price reported for the applicable transaction have been adjusted to reflect the April Reverse Stock Split. ( 4 )Represents shares withheld to satisfy tax liabilities associated with the reported vesting of restricted stock units on the applicable transaction date. ( 5 )On October 16, 2023, the reporting person was granted 84 restricted stock units, vesting in three annual installments beginning on the first anniversary of the grant date. 33% of the restricted stock units vested on October 16, 2024, an additional 33% of the restricted stock units vested on October 16, 2025, and the remaining balance of 34% of the restricted stock units will vest on October 16, 2026. Vesting will be accelerated upon certain termination of employment events and upon a "Change in Control" (as defined in the Direct Digital Holdings, Inc. 2022 Omnibus Incentive Plan). This grant was previously reported as covering 18,650 restricted stock units, but was adjusted to reflect the Reverse Stock Splits. ( 6 )On January 24, 2025, the reporting person was granted 102 restricted stock units, vesting on the first anniversary of the grant date conditioned on continued employment as of the vesting date. All of the restricted stock units vested on January 24, 2026. This grant was previously reported as covering 22,500 restricted stock units, but was adjusted to reflect the Reverse Stock Splits. ( 7 )This option is scheduled to vest in three equal annual installments beginning on March 24, 2027. ( 8 )On April 1, 2025, the reporting person was granted 101 restricted stock units, vesting in three annual installments beginning on the first anniversary of the grant date. 33% of the restricted stock units vested on April 1, 2026, an additional 33% of the restricted stock units will vest on April 1, 2027, and the remaining balance of 34% of the restricted stock units will vest on April 1, 2028. Vesting will be accelerated upon certain termination of employment events and upon a "Change in Control" (as defined in the Direct Digital Holdings, Inc. 2022 Omnibus Incentive Plan). This grant was previously reported as covering 22,500 restricted stock units, but was adjusted to reflect the Reverse Stock Splits.

Remarks: The Reporting Person is hereby disclosing delinquent transactions reportable on Form 4 that were not reported due to an administrative oversight.

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.