Grant Douglas Thoele - Oct 1, 2025 Form 4 Insider Report for ASPEN AEROGELS INC (ASPN)

Role: CFO & Treasurer
Signature: /s/ Glenn Deegan, Attorney-in-Fact
Stock symbol: ASPN
Transactions as of: Oct 1, 2025
Transactions value $: $0
Form type: 4
Date filed: 10/3/2025, 05:00 PM
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Thoele Grant Douglas	CFO & Treasurer	30 FORBES ROAD, BUILDING B, NORTHBOROUGH	/s/ Glenn Deegan, Attorney-in-Fact	2025-10-03	0002089743

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ASPN	Common Stock	Award	$0	+10.3K	+222.94%	$0.00	14.9K	Oct 1, 2025	Direct	F1, F2

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	+14.6K		$0.00	14.6K	Oct 1, 2025	Common Stock	14.6K	$7.30	Direct	F3
transaction	ASPN	Performance Share Units	Award	$0	+20.5K		$0.00	20.5K	Oct 1, 2025	Common Stock	20.5K		Direct	F4

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

Explanation of Responses:

Id	Content
F1	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.
F2	Represents 4,608 shares of Common Stock and 10,273 RSUs.
F3	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.
F4	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.