{"transactions":[{"id":851655,"issuer":{"id":5645,"kind":"organization","name":"ASPEN AEROGELS INC","symbol":"ASPN"},"owners":[{"id":61820,"kind":"person","name":"Thoele Grant Douglas","position":1,"cik":"0002089743","reported_name":"Thoele Grant Douglas","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Treasurer"}}],"security":"Common Stock","published_at":"2026-03-10T21:00:08.000Z","date":"2026-03-08","kind":"tax_withholding","planned":false,"acquired":false,"shares":590,"price":3.22,"value":1899.8,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Shares withheld by Registrant to satisfy the minimum statutory tax withholding requirements on vesting of Restricted Stock Units (\"RSUs\")."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Represents 10,111 shares of Common Stock and 67,621 RSUs."}],"balance_after":77732,"source":{"system":"sec-edgar","filing":"0001193125-26-100342","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1145986/000119312526100342/ownership.xml","form_type":"4"}},{"id":856488,"issuer":{"id":5645,"kind":"organization","name":"ASPEN AEROGELS INC","symbol":"ASPN"},"owners":[{"id":61820,"kind":"person","name":"Thoele Grant Douglas","position":1,"cik":"0002089743","reported_name":"Thoele Grant Douglas","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Treasurer"}}],"security":"Stock Options (Right to Buy)","published_at":"2026-03-06T22:00:05.000Z","date":"2026-03-04","kind":"grant","planned":false,"acquired":true,"shares":74893,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"The options vest as to one-third of the shares on March 4, 2027, an additional one-third of the shares on March 4, 2028 and the remaining one-third of the shares on March 4, 2029."}],"balance_after":74893,"derivative":{"exercise_price":3.35,"expiration_date":"2036-03-04","underlying":"Common Stock","underlying_shares":74893},"source":{"system":"sec-edgar","filing":"0001193125-26-096816","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1145986/000119312526096816/ownership.xml","form_type":"4"}},{"id":856487,"issuer":{"id":5645,"kind":"organization","name":"ASPEN AEROGELS INC","symbol":"ASPN"},"owners":[{"id":61820,"kind":"person","name":"Thoele Grant Douglas","position":1,"cik":"0002089743","reported_name":"Thoele Grant Douglas","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Treasurer"}}],"security":"Common Stock","published_at":"2026-03-06T22:00:05.000Z","date":"2026-03-05","kind":"tax_withholding","planned":false,"acquired":false,"shares":2368,"price":3.27,"value":7743.36,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F2","text":"Shares withheld by Registrant to satisfy the minimum statutory tax withholding requirements on vesting of Restricted Stock Units (\"RSUs\")."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Represents 9,014 shares of Common Stock and 69,308 RSUs."}],"balance_after":78322,"source":{"system":"sec-edgar","filing":"0001193125-26-096816","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1145986/000119312526096816/ownership.xml","form_type":"4"}},{"id":856486,"issuer":{"id":5645,"kind":"organization","name":"ASPEN AEROGELS INC","symbol":"ASPN"},"owners":[{"id":61820,"kind":"person","name":"Thoele Grant Douglas","position":1,"cik":"0002089743","reported_name":"Thoele Grant Douglas","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Treasurer"}}],"security":"Common Stock","published_at":"2026-03-06T22:00:05.000Z","date":"2026-03-04","kind":"grant","planned":false,"acquired":true,"shares":55298,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"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 4, 2027, an additional one-third of the shares on March 4, 2028 and the remaining one-third of the shares on March 4, 2029."}],"balance_after":80690,"source":{"system":"sec-edgar","filing":"0001193125-26-096816","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1145986/000119312526096816/ownership.xml","form_type":"4"}},{"id":962304,"issuer":{"id":5645,"kind":"organization","name":"ASPEN AEROGELS INC","symbol":"ASPN"},"owners":[{"id":61820,"kind":"person","name":"Thoele Grant Douglas","position":1,"cik":"0002089743","reported_name":"Thoele Grant Douglas","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Treasurer"}}],"security":"Common Stock","published_at":"2025-12-19T22:15:04.000Z","date":"2025-10-01","kind":"grant","planned":false,"acquired":true,"shares":10273,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"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."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"This Form 4/A is being filed to correct the reported total of Securities Beneficially Owned following the reported transaction. The beneficially owned shares previously reported did not include 10,511 restricted stock units granted prior to the October 1, 2025, transaction date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Represents 4,608 shares of Common Stock and 20,784 RSUs."}],"balance_after":25392,"source":{"system":"sec-edgar","filing":"0001193125-25-327079","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1145986/000119312525327079/ownership.xml","form_type":"4/A","original_submission_date":"2025-10-03"}},{"id":1025231,"issuer":{"id":5645,"kind":"organization","name":"ASPEN AEROGELS INC","symbol":"ASPN"},"owners":[{"id":61820,"kind":"person","name":"Thoele Grant Douglas","position":1,"cik":"0002089743","reported_name":"Thoele Grant Douglas","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Treasurer"}}],"security":"Performance Share Units","published_at":"2025-10-03T21:00:09.000Z","date":"2025-10-01","kind":"grant","planned":false,"acquired":true,"shares":20547,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F4","text":"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."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"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."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F4","text":"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."}],"balance_after":20547,"derivative":{"underlying":"Common Stock","underlying_shares":20547},"source":{"system":"sec-edgar","filing":"0001193125-25-230376","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1145986/000119312525230376/ownership.xml","form_type":"4"}},{"id":1025230,"issuer":{"id":5645,"kind":"organization","name":"ASPEN AEROGELS INC","symbol":"ASPN"},"owners":[{"id":61820,"kind":"person","name":"Thoele Grant Douglas","position":1,"cik":"0002089743","reported_name":"Thoele Grant Douglas","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Treasurer"}}],"security":"Stock Options (Right to Buy)","published_at":"2025-10-03T21:00:09.000Z","date":"2025-10-01","kind":"grant","planned":false,"acquired":true,"shares":14563,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"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."}],"balance_after":14563,"derivative":{"exercise_price":7.3,"expiration_date":"2035-10-01","underlying":"Common Stock","underlying_shares":14563},"source":{"system":"sec-edgar","filing":"0001193125-25-230376","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1145986/000119312525230376/ownership.xml","form_type":"4"}},{"id":1025229,"issuer":{"id":5645,"kind":"organization","name":"ASPEN AEROGELS INC","symbol":"ASPN"},"owners":[{"id":61820,"kind":"person","name":"Thoele Grant Douglas","position":1,"cik":"0002089743","reported_name":"Thoele Grant Douglas","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"CFO & Treasurer"}}],"security":"Common Stock","published_at":"2025-10-03T21:00:09.000Z","date":"2025-10-01","kind":"grant","planned":false,"acquired":true,"shares":10273,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"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."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Represents 4,608 shares of Common Stock and 10,273 RSUs."}],"balance_after":14881,"source":{"system":"sec-edgar","filing":"0001193125-25-230376","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1145986/000119312525230376/ownership.xml","form_type":"4"}}]}