Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in ASPN held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | KIM, LLC | 12.3M | $42.0M | 0.0% | 14.818% | 6.19% |
| 2 | OAKTOP CAPITAL MANAGEMENT II, L.P. | 5.2M | $17.7M | +17.6% | 6.236% | 1.32% |
| 3 | BlackRock, Inc. | 4.7M | $16.2M | -3.8% | 5.723% | 0.00% |
| 4 | NEEDHAM INVESTMENT MANAGEMENT LLC | 4.5M | $15.5M | +3.8% | 5.452% | 0.79% |
| 5 | VANGUARD CAPITAL MANAGEMENT LLC | 3.4M | $11.8M | β | 4.146% | 0.00% |
| 6 | GEORGE KAISER FAMILY FOUNDATION | 3.2M | $10.8M | 0.0% | 3.822% | 1.23% |
| 7 | STATE STREET CORP | 2.3M | $7.9M | -7.2% | 2.800% | 0.00% |
| 8 | Invesco Ltd. | 2.3M | $7.9M | -44.4% | 2.773% | 0.00% |
| 9 | GAGNON SECURITIES LLC | 1.9M | $6.4M | +64.3% | 2.246% | 1.47% |
| 10 | RICE HALL JAMES & ASSOCIATES, LLC | 1.6M | $5.3M | +9.2% | 1.873% | 0.30% |
| 11 | GEODE CAPITAL MANAGEMENT, LLC | 1.5M | $5.3M | -3.8% | 1.859% | 0.00% |
| 12 | AMERIPRISE FINANCIAL INC | 1.5M | $5.2M | +9.3% | 1.818% | 0.00% |
| 13 | MILLENNIUM MANAGEMENT LLC | 1.4M | $4.8M | +61.3% | 1.695% | 0.00% |
| 14 | MARSHALL WACE, LLP | 1.3M | $4.3M | +127.9% | 1.524% | 0.00% |
| 15 | DIMENSIONAL FUND ADVISORS LP | 1.3M | $4.3M | -37.3% | 1.516% | 0.00% |
| 16 | AMERICAN CENTURY COMPANIES INC | 1.2M | $4.3M | +7.8% | 1.506% | 0.00% |
| 17 | JACOBS LEVY EQUITY MANAGEMENT, INC | 1.2M | $4.2M | +769.9% | 1.471% | 0.02% |
| 18 | Telemark Asset Management, LLC | 1.0M | $3.4M | 0.0% | 1.207% | 0.32% |
| 19 | ROYCE & ASSOCIATES LP | 987K | $3.4M | β | 1.190% | 0.03% |
| 20 | GOLDMAN SACHS GROUP INC | 900K | $3.1M | -30.5% | 1.085% | 0.00% |
| 21 | D. E. Shaw & Co., Inc. | 834K | $2.9M | +3490.3% | 1.006% | 0.00% |
| 22 | VANGUARD PORTFOLIO MANAGEMENT LLC | 717K | $2.5M | β | 0.865% | 0.00% |
| 23 | BNP PARIBAS ARBITRAGE, SA | 698K | $2.4M | +1.0% | 0.842% | 0.00% |
| 24 | Samjo Management, LLC | 646K | $2.2M | -19.1% | 0.779% | 0.95% |
| 25 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 557K | $1.9M | +3.0% | 0.672% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in ASPN β a direct measure of their conviction.
Filings activity in ASPN during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 161 | 10% | 46.74% | +6.23 pp | $229M | +15% |
| Q4 2025 | 179 | 10% | 40.51% | 62.13 pp | $199M | 61% |
| Q3 2025 | 199 | +9.3% | 102.64% | +18.12 pp | $504M | +21% |
| Q2 2025 | 182 | 17% | 84.52% | 6.99 pp | $415M | 7.6% |
| Q1 2025 | 219 | 2.7% | 91.51% | 88.17 pp | $449M | 49% |
| Q4 2024 | 225 | 5.5% | 179.68% | 20.31 pp | $882M | 54% |
| Q3 2024 | 238 | +11% | 199.99% | +0.00 pp | $1.90B | +13% |
| Q2 2024 | 214 | β | 199.99% | β | $1.69B | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying ASPN stock.
Based on Q1 2026 13F filings, institutional ownership of Aspen Aerogels, Inc. stands at 46.7%, held across 161 reporting institutions.
KIM, LLC is the largest reported institutional holder of ASPN, with approximately 12,280,426 shares worth $0.04B as of Q1 2026.
Yes β 1 widely-followed marquee investor appear among the top 25 institutional holders of ASPN, including MILLENNIUM MANAGEMENT LLC.
Our composite Smart Money Score for ASPN is 52 out of 100 (Neutral). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
38 institutions opened new positions in ASPN during Q1 2026, while 56 fully exited. 89 added to existing positions and 33 trimmed.
ASPN institutional ownership rose by 6.23 percentage points quarter-over-quarter, with a net change of -18 holders.
The top 10 institutions account for 61.7% of all reported 13F value in ASPN, and the top 25 account for 85.2%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Aspen Aerogels, Inc. (ASPN) Institutional Ownership