Santhosh P. Daniel - 05 Mar 2025 Form 4 Insider Report for ASPEN AEROGELS INC (ASPN)

Role: Chief Accounting Officer
Signature: /s/ Virginia H. Johnson, Attorney-in-Fact
Issuer symbol: ASPN
Transactions as of: 05 Mar 2025
Net transactions value: -$3,356
Form type: 4
Filing time: 07 Mar 2025, 16:50:26 UTC
Previous filing: 16 Sep 2024
Next filing: 13 Aug 2025
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ASPN	Common Stock	Tax liability	$3,356	-428	-2.1%	$7.84	19,506	05 Mar 2025	Direct	F1
transaction	ASPN	Common Stock	Award	$0	+4,783	+25%	$0.000000	24,289	05 Mar 2025	Direct	F2, F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	ASPN	Stock Options (Right to Buy)	Award	$0	+6,742		$0.000000	6,742	05 Mar 2025	Common Stock	6,742	$7.84	Direct	F4
transaction	ASPN	Performance Share Units	Award	$0	+9,566		$0.000000	9,566	05 Mar 2025	Common Stock	9,566		Direct	F5

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Shares withheld by Registrant to satisfy the minimum statutory tax withholding requirements on vesting of Restricted Stock Units ("RSUs").
F2	Each Restricted Stock Unit ("RSU") represents the right to receive one share of Common Stock upon vesting. The RSUs vest as to one-third of the shares on March 5, 2026, an additional one-third of the shares on March 5, 2027 and the remaining one-third of the shares on March 5, 2028.
F3	Represents 6,410 shares of Common Stock and 17,879 RSUs.
F4	The options vest as to one-third of the shares on March 5, 2026, an additional one-third of the shares on March 5, 2027 and the remaining one-third of the shares on March 5, 2028.
F5	Each performance share unit ("PSU") represents a contingent right to receive one share of Common Stock upon vesting. The PSUs vest on March 5, 2028, following the completion of the performance period, which begins on January 1, 2025 and ends on December 31, 2027. Ranging between 0-200% of the target number of PSUs (as reflected in Table II above), the PSUs vest based on the total shareholder return of Common Stock relative to the total stockholder return of the components of the Russell 2000 Index.