Aspen Aerogels, Inc.
US ˙ NYSE ˙ US04523Y1055

SecurityASPN / Aspen Aerogels, Inc.
InstitutionOppenheimer & Co Inc
Latest Disclosed Ownership76,284 shares
Latest Disclosed Value $ 260,891
Oppenheimer & Co Inc reports 0.96% decrease in ownership of ASPN / Aspen Aerogels, Inc.

On April 23, 2026 - Oppenheimer & Co Inc filed a 13F-HR form disclosing ownership of 76,284 shares of Aspen Aerogels, Inc. (US:ASPN) valued at $260,891 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 2, 2026 disclosing 77,021 shares of Aspen Aerogels, Inc.. This represents a change in shares of -0.96% during the quarter. The current value of the position is $430,242 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-04-23 2026-03-31 13F ASPEN AEROGELS COM 04523Y105 76,284 -737 -0.96 261 19.82 0.0032
2026-02-02 2025-12-31 13F ASPEN AEROGELS COM 04523Y105 77,021 -44,805 -36.78 218 -74.38 0.0031
2025-11-06 2025-09-30 13F ASPEN AEROGELS COM 04523Y105 121,826 102,047 515.94 848 623.93 0.0103
2025-07-31 2025-06-30 13F ASPEN AEROGELS COM 04523Y105 19,779 -183,381 -90.26 117 -90.99 0.0015
2025-04-23 2025-03-31 13F ASPEN AEROGELS COM 04523Y105 203,160 21,632 11.92 1,298 -39.80 0.0196
2025-02-05 2024-12-31 13F ASPEN AEROGELS COM 04523Y105 181,528 78,993 77.04 2,157 -24.06 0.0322
2024-11-05 2024-09-30 13F ASPEN AEROGELS COM 04523Y105 102,535 64,154 167.15 2,839 210.27 0.0433
2024-08-08 2024-06-30 13F ASPEN AEROGELS COM 04523Y105 38,381 16,326 74.02 915 135.82 0.0145
2024-05-07 2024-03-31 13F ASPEN AEROGELS COM 04523Y105 22,055 22,055 388 0.0064
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.