ETERGINO THOMAS J (Chief Financial Officer) exercised options at 1STDIBS.COM, INC.

Option exercise — a mechanical event triggered by vesting or expiry. Not a discretionary conviction trade.

M · 4 exercises

ETERGINO THOMAS J

Filed: 6/10/2026ACC: 0001336088-26-000006

InsiderETERGINO THOMAS JCIK 1336088

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Issuer1STDIBS.COM, INC.CIK 1600641

Officer· Chief Financial Officer

Since Mar 2022

-18.40K

Net shares

Net seller

$73.8K

Total sold

Open market trades

0B · 0S

Total transactions

51.03K acquired · 69.44K disposed

Non-Derivative Transactions5

Common Stock

Direct

M · Option Exercise

+11.18K

Price / share

—

Trade value

—

% of position

3.7%

6/8/2026

300.79K→311.96K

Common Stock

Direct

M · Option Exercise

+11.17K

Price / share

—

Trade value

—

% of position

3.6%

6/8/2026

311.96K→323.13K

Common Stock

Direct

M · Option Exercise

+12.13K

Price / share

—

Trade value

—

% of position

3.8%

6/8/2026

323.13K→335.26K

Common Stock

Direct

M · Option Exercise

+16.56K

Price / share

—

Trade value

—

% of position

4.9%

6/8/2026

335.26K→351.82K

Common Stock

Direct

F · Tax Withholding

−18.40K

Price / share

$4.01

Trade value

$73.78K

% of position

5.2%

6/8/2026

351.82K→333.42K

Total

Net shares

+32.63K

Net value

-$73.78K

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Common Stock Direct	6/8/2026	M · Option Exercise	+11.18K	—	—	3.7%	300.79K	311.96K
Common Stock Direct	6/8/2026	M · Option Exercise	+11.17K	—	—	3.6%	311.96K	323.13K
Common Stock Direct	6/8/2026	M · Option Exercise	+12.13K	—	—	3.8%	323.13K	335.26K
Common Stock Direct	6/8/2026	M · Option Exercise	+16.56K	—	—	4.9%	335.26K	351.82K
Common Stock Direct	6/8/2026	F · Tax Withholding	−18.40K	$4.01	$73.78K	5.2%	351.82K	333.42K
Total			+32.63K		-$73.78K

Derivative Transactions4

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Common Stock

11.18K shares

−11.18K

Strike price

Held after

78.22K

Exercisable

—

6/8/2026

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Common Stock

11.17K shares

−11.17K

Strike price

Held after

122.89K

Exercisable

—

6/8/2026

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Common Stock

12.13K shares

−12.13K

Strike price

Held after

133.38K

Exercisable

—

6/8/2026

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Common Stock

16.56K shares

−16.56K

Strike price

Held after

0.00

Exercisable

—

6/8/2026

Security	Converts To	Date	Type	Shares	Exercisable	Held After
Restricted Stock Units Direct	Common Stock11.18K shares	6/8/2026	M · Option Exercise	−11.18K	—	78.22K
Restricted Stock Units Direct	Common Stock11.17K shares	6/8/2026	M · Option Exercise	−11.17K	—	122.89K
Restricted Stock Units Direct	Common Stock12.13K shares	6/8/2026	M · Option Exercise	−12.13K	—	133.38K
Restricted Stock Units Direct	Common Stock16.56K shares	6/8/2026	M · Option Exercise	−16.56K	—	0.00