[Form 4] 1stdibs.com, Inc. Insider Trading Activity

Rhea-AI Filing Summary

David S. Rosenblatt, CEO and Director of 1stdibs.com, Inc. (DIBS), reported multiple transactions on Form 4 dated 09/08/2025 reflecting receipt and vesting of restricted stock units and a single open-market disposition. The filing shows three separate grant-related vesting events that together added 132,500 vested RSUs (37,500; 47,500; 47,500), increasing his direct beneficial RSU counts to 225,000, 475,000 and 665,000 respectively, and raising direct common stock holdings in steps to as many as 1,919,105 shares after the reported acquisitions.

The filing also discloses an open-market sale of 73,207 shares at $2.80 per share, with 22,500 shares held indirectly by the Laura Thalheimer Rosenblatt Family Trust and 665,302 shares indirectly by the David Rosenblatt Family Trust. Transactions were signed by Melanie Goins on behalf of Mr. Rosenblatt on 09/10/2025.

Positive

• Significant insider ownership retained with reported beneficial ownership totals exceeding 1.8 million shares in multiple lines
• Multiple RSU vesting events increase direct holdings, indicating continued compensation alignment with the company

Negative

• Open-market sale of 73,207 shares at $2.80 per share reduced direct holdings
• Net share withholding for taxes indicates shares were retained by the issuer rather than sold in the open market to cover tax obligations

Insights

Financial Analyst

TL;DR: Routine executive compensation vesting with a small open-market sale; overall insider stake remains substantial.

The report documents standard vesting of RSUs across three grants and corresponding increases in direct beneficial ownership. The open-market sale of 73,207 shares at $2.80 reduces direct holdings modestly relative to the total reported stake above one million shares. For investors this appears as compensation-related vesting rather than activity suggesting a change in corporate outlook.

Corporate Governance Expert

TL;DR: Disclosure aligns with Section 16 requirements; vesting schedules and trust holdings are properly reported.

The Form 4 provides clear coding for M (vesting/issuance) and S (sale) transactions, explains net withholding for tax obligations, and discloses indirect holdings via family trusts. The disclosures include vesting schedules and confirm no open-market sale was used to satisfy taxes (shares were retained by the issuer for withholding). Filing appears compliant and complete for the events reported.

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
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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^*

ROSENBLATT DAVID S

(Last) (First) (Middle)

300 PARK AVENUE SOUTH

10TH FLOOR

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
1stdibs.com, Inc. [ DIBS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
09/08/2025

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	09/08/2025		M		37,500	A	(1)	1,824,105	D
Common Stock	09/08/2025		M		47,500	A	(1)	1,871,605	D
Common Stock	09/08/2025		M		47,500	A	(1)	1,919,105	D
Common Stock	09/08/2025		S		73,207(2)	D	$2.8	1,845,898	D
Common Stock								22,500	I	By 2024 Laura Thalheimer Rosenblatt Family Trust effective 4/1/2024
Common Stock								665,302	I	By 2012 David Rosenblatt Family Trust dtd 11/30/2012

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
Restricted Stock Units	(1)	09/08/2025		M			37,500	(3)	(3)	Common Stock	37,500	$0	225,000	D
Restricted Stock Units	(1)	09/08/2025		M			47,500	(4)	(4)	Common Stock	47,500	$0	475,000	D
Restricted Stock Units	(1)	09/08/2025		M			47,500	(5)	(5)	Common Stock	47,500	$0	665,000	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of Issuer common stock.

2. These shares were retained by Issuer via settlement on a net withholding basis in order to meet the tax withholding obligations of the reporting person in connection with the vesting of an installment of restricted stock units ("RSUs") granted to the reporting person on March 15, 2023, March 8, 2024 and March 14, 2025. None of these shares were sold in an open market transaction.

3. The initial number of restricted stock units granted shall vest in 16 equal quarterly installments starting on June 8, 2023, provided the Reporting Person continues to have a service relationship with the Issuer at such time. The restricted stock units have no expiration date.

4. The initial number of restricted stock units granted shall vest in 16 equal quarterly installments starting on June 8, 2024, provided the Reporting Person continues to have a service relationship with the Issuer at such time. The restricted stock units have no expiration date.

5. The initial number of restricted stock units granted shall vest in 16 equal quarterly installments starting on June 8, 2025, provided the Reporting Person continues to have a service relationship with the Issuer at such time. The restricted stock units have no expiration date.

Remarks:

	/s/ Melanie Goins, Attorney-In-Fact for David S. Rosenblatt	09/10/2025
	** 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.
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FAQ

What transactions did David S. Rosenblatt report on Form 4 for DIBS?

The Form 4 reports vesting/issuance of RSUs totaling 132,500 vested units across three grant tranches and an open-market sale of 73,207 common shares at $2.80 per share.

How many shares does Rosenblatt beneficially own after these transactions?

The filing shows various reported post-transaction totals by line, with direct beneficial ownership figures reported as high as 1,919,105 shares following the acquisitions.

Were any shares withheld to cover taxes on vested RSUs?

Yes. The filing states the issuer retained shares via net settlement to satisfy tax withholding obligations related to RSU vesting; these retained shares were not sold in the open market.

Does Rosenblatt hold shares indirectly through trusts?

Yes. The filing discloses 22,500 shares indirect via the Laura Thalheimer Rosenblatt Family Trust (effective 4/1/2024) and 665,302 shares indirect via the David Rosenblatt Family Trust (dated 11/30/2012).

When were the reported transactions executed and when was the Form 4 signed?

The transactions are reported with a transaction date of 09/08/2025 and the Form 4 was signed on 09/10/2025 by Melanie Goins, Attorney-In-Fact.