# EDGAR Filing Document

**Accession Number:** 0001145986
**File Stem:** 0001193125-25-228693
**Filing Date:** 2025-10
**Character Count:** 9794
**Document Hash:** 2b93953287e238a255370e33cd7008dd
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-228693.hdr.sgml**: 20251002

**ACCESSION NUMBER**: 0001193125-25-228693

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20251001

**FILED AS OF DATE**: 20251002

**DATE AS OF CHANGE**: 20251002

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Thoele Grant Douglas
- **CENTRAL INDEX KEY:** 0002089743

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36481
- **FILM NUMBER:** 251370876

**MAIL ADDRESS:**
- **STREET 1:** 30 FORBES ROAD, BUILDING B
- **CITY:** NORTHBOROUGH
- **STATE:** MA
- **ZIP:** 01532
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ASPEN AEROGELS INC
- **CENTRAL INDEX KEY:** 0001145986
- **STANDARD INDUSTRIAL CLASSIFICATION:** WHOLESALE-LUMBER & OTHER CONSTRUCTION MATERIALS [5030]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 043559972
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 30 FORBES ROAD
- **STREET 2:** BUILDING B
- **CITY:** NORTHBOROUGH
- **STATE:** MA
- **ZIP:** 01532
- **BUSINESS PHONE:** 5086911111

**MAIL ADDRESS:**
- **STREET 1:** 30 FORBES ROAD
- **STREET 2:** BUILDING B
- **CITY:** NORTHBOROUGH
- **STATE:** MA
- **ZIP:** 01532

## Exhibit 24.1

**Exhibit 24**

**POWER OF ATTORNEY**

Know all by these presents, that the undersigned hereby constitutes and appoints Glenn Deegan, Chief Administrative Officer, General Counsel and Corporate Secretary, and Andrew Lauzon, Senior Director, Total Reward, of Aspen Aerogels, Inc. (the "Company"), signing singly, with full power of substitution, the undersigned's true and lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, forms and authentication documents for EDGAR Filing Access;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) do and perform any and all acts for and on behalf of the undersigned which may be necessary or desirable to complete and execute any such forms and authentication documents;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) execute for and on behalf of the undersigned, in the undersigned's capacity as an officer, director and/or 10% shareholder of the Company, Forms 3, 4 and 5 in accordance with Section 16(a) of the Securities Exchange Act of 1934 and the rules thereunder;

(4) do and perform any and all acts for and on behalf of the undersigned which may be necessary or desirable to complete and execute any such Form 3, 4 or 5 and timely file such form with the United States Securities and Exchange Commission and any stock exchange or similar authority; and

(5) take any other action of any type whatsoever in connection with the foregoing which, in the opinion of such attorney-in-fact, may be of benefit to, in the best interest of, or legally required by, the undersigned, it being understood that the documents executed by such attorney-in-fact, on behalf of the undersigned pursuant to this Power of Attorney, shall be in such form and shall contain such terms and conditions as such attorney-in-fact may approve in such attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact full power and authority to do and perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that such attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be done by virtue of this power of attorney and the rights and powers herein granted. The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in such capacity at the request of the undersigned, is not assuming, nor is the Company assuming, any of the undersigned's responsibilities to comply with Section 16 of the Securities Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file Forms 3, 4 and 5 with respect to the undersigned's holdings of and transactions in securities issued by the Company, unless earlier revoked by the undersigned in a signed writing delivered to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed this 1<sup>st</sup> day of October, 2025.

By: /s/ Grant Thoele

Name: Grant Thoele

Title: Chief Financial Officer and Treasurer

------

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Thoele Grant Douglas<br><sub>(Last) (First) (Middle)</sub><br>30 FORBES ROAD, BUILDING B<br><sub>(Street)</sub><br>NORTHBOROUGH, MA 01532<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>ASPEN AEROGELS INC [ ASPN ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2025-10-01 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director   [ ] 10% Owner<br>[X] Officer (give title below)   [ ] Other (specify below)<br>_CFO & Treasurer_ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |
| Common Stock | 4608 | D |  |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| Stock Options (Right to Buy) | <sup>(1)</sup> | 2031-11-02 | Common Stock | 1001 | $52.60 | D |  |
| Stock Options (Right to Buy) | <sup>(2)</sup> | 2032-02-23 | Common Stock | 1327 | $26.29 | D |  |
| Stock Options (Right to Buy) | <sup>(2)</sup> | 2032-02-23 | Common Stock | 2987 | $26.29 | D |  |
| Stock Options (Right to Buy) | <sup>(3)</sup> | 2033-03-08 | Common Stock | 7768 | $9.88 | D |  |
| Stock Options (Right to Buy) | <sup>(4)</sup> | 2034-03-05 | Common Stock | 5371 | $16.34 | D |  |
| Stock Options (Right to Buy) | <sup>(5)</sup> | 2035-03-05 | Common Stock | 8990 | $7.84 | D |  |
| Performance Share Units | 2028-03-05<sup>(6)</sup> | <sup>(6)</sup> | Common Stock | 12755 | <sup>(6)</sup> | D |  |

---

### Footnotes:

(1) These options to purchase shares of our common stock were granted on November 2, 2021 and vested as to one-third of the shares on each anniversary of the grant date until November 2, 2024.

(2) These options to purchase shares of our common stock were granted on February 23, 2022 and vested as to one-third of the shares on each anniversary of the grant date until February 23, 2025.

(3) These options to purchase shares of our common stock were granted on March 8, 2023 and vested as to one-third of the shares on each anniversary of the grant date until March 8, 2026.

(4) These options to purchase shares of our common stock were granted on March 5, 2024 and vested as to one-third of the shares on each anniversary of the grant date until March 5, 2027.

(5) These options to purchase shares of our common stock were granted on March 5, 2025 and vested as to one-third of the shares on each anniversary of the grant date until March 5, 2028.

(6) 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.

**Remarks:**
Exhibit 24.1 - Power of Attorney

**Signature:** /s/ Glenn Deegan, Attorney-in-Fact  
**Date:** 2025-10-02

### Remarks:

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.**