Who owns Aspen Aerogels (ASPN)
Which tracked institutional funds hold ASPN, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ASPN company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on ASPN is one-sided between 2026-Q1 and 2026-Q2: 62 added or opened and 9 trimmed or exited — on balance accumulating.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
ASPN’s largest tracked holder by dollar value, KIM, LLC, sizes it at 22.2% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 22.2pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ASPN divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 175 tracked filers holding ASPN, 97 increased or opened the position and 72 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in ASPN between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 7
- Baird Financial Group, Inc.$2M
- Trexquant Investment LP$2M
- RENAISSANCE TECHNOLOGIES LLC$2M
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$1M
- Jump Financial, LLC$1M
- Jefferies Financial Group Inc.$801K
Full exits 4
- HRT FINANCIAL LP$3M
- Samjo Management, LLC$2M
- JANE STREET GROUP, LLC$642K
- Engineers Gate Manager LP$507K
Largest adds
- KIM, LLC$36M
- BlackRock, Inc.$17M
- OAKTOP CAPITAL MANAGEMENT II, L.P.$15M
- AMERICAN CENTURY COMPANIES INC$12M
- VANGUARD CAPITAL MANAGEMENT LLC$11M
- George Kaiser Family Foundation$9M
Largest trims
- Point72 Asset Management, L.P.$821K
- CITADEL ADVISORS LLC$474K
- EverSource Wealth Advisors, LLC$377K
- Palogic Value Management, L.P.$362K
- HSBC HOLDINGS PLC$273K
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| KIM, LLC | 12,280,426 | $78M | 17.0% | 2026-Q2 |
| BlackRock, Inc. added | 5,277,148 | $33M | 7.3% | 2026-Q2 |
| OAKTOP CAPITAL MANAGEMENT II, L.P. | 5,168,674 | $33M | 7.2% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 3,539,271 | $22M | 4.9% | 2026-Q2 |
| NEEDHAM INVESTMENT MANAGEMENT LLC trimmed | 3,260,800 | $21M | 4.5% | 2026-Q2 |
| George Kaiser Family Foundation | 3,167,322 | $20M | 4.4% | 2026-Q2 |
| STATE STREET CORP added | 2,559,495 | $16M | 3.5% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC added | 2,510,042 | $16M | 3.5% | 2026-Q2 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 2,058,083 | $13M | 2.9% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 1,821,295 | $12M | 2.5% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,770,425 | $11M | 2.5% | 2026-Q2 |
| RICE HALL JAMES & ASSOCIATES, LLC added | 1,635,259 | $10M | 2.3% | 2026-Q2 |
| Invesco Ltd. trimmed | 1,619,972 | $10M | 2.2% | 2026-Q2 |
| GAGNON SECURITIES LLC trimmed | 1,535,812 | $10M | 2.1% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 1,447,333 | $9M | 2.0% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 1,372,300 | $9M | 1.9% | 2026-Q2 |
| ROYCE & ASSOCIATES LP added | 1,323,218 | $8M | 1.8% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC added | 1,276,346 | $8M | 1.8% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 1,190,616 | $8M | 1.6% | 2026-Q2 |
| MARSHALL WACE, LLP trimmed | 1,146,707 | $7M | 1.6% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 1,066,501 | $7M | 1.5% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 1,004,383 | $6M | 1.3% | 2026-Q2 |
| Telemark Asset Management, LLC | 1,000,000 | $6M | 1.4% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS added | 867,199 | $5M | 1.2% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 779,468 | $5M | 1.1% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC trimmed | 698,983 | $4M | 1.0% | 2026-Q2 |
| FEDERATED HERMES, INC. added | 596,883 | $4M | 0.8% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 570,712 | $4M | 0.8% | 2026-Q2 |
| TUDOR INVESTMENT CORP ET AL added | 567,384 | $4M | 0.8% | 2026-Q2 |
| NORTHERN TRUST CORP added | 565,569 | $4M | 0.8% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 474,393 | $3M | 0.7% | 2026-Q2 |
| PANAGORA ASSET MANAGEMENT INC added | 442,448 | $3M | 0.6% | 2026-Q2 |
| MORGAN STANLEY added | 397,075 | $3M | 0.6% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 372,077 | $2M | 0.5% | 2026-Q2 |
| Baird Financial Group, Inc. added | 345,193 | $2M | 0.5% | 2026-Q2 |
| ALGERT GLOBAL LLC trimmed | 302,582 | $2M | 0.4% | 2026-Q2 |
| Trexquant Investment LP added | 302,439 | $2M | 0.4% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC added | 274,392 | $2M | 0.4% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ added | 252,746 | $2M | 0.4% | 2026-Q2 |
| CITADEL ADVISORS LLC trimmed | 238,731 | $2M | 0.3% | 2026-Q2 |
| PRUDENTIAL FINANCIAL INC added | 229,935 | $1M | 0.3% | 2026-Q2 |
| XTX Topco Ltd added | 227,977 | $1M | 0.3% | 2026-Q2 |
| FIRST TRUST ADVISORS LP added | 222,352 | $1M | 0.3% | 2026-Q2 |
| Bank of New York Mellon Corp added | 195,389 | $1M | 0.3% | 2026-Q2 |
| Palogic Value Management, L.P. trimmed | 185,589 | $1M | 0.3% | 2026-Q2 |
| CITIGROUP INC trimmed | 181,651 | $1M | 0.3% | 2026-Q2 |
| IRONWOOD INVESTMENT MANAGEMENT LLC added | 179,301 | $1M | 0.2% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 177,419 | $1M | 0.2% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP new | 171,150 | $1M | 0.2% | 2026-Q2 |
| Jump Financial, LLC trimmed | 168,865 | $1M | 0.2% | 2026-Q2 |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 157,400 | $998K | 0.2% | 2026-Q2 |
| Nuveen, LLC added | 145,324 | $921K | 0.2% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 130,300 | $827K | 0.2% | 2026-Q2 |
| PUBLIC EMPLOYEES RETIREMENT SYSTEM OF OHIO added | 128,107 | $812K | 0.2% | 2026-Q2 |
| Jefferies Financial Group Inc. new | 126,303 | $801K | 0.2% | 2026-Q2 |
| Firsthand Capital Management, Inc. | 125,000 | $792K | 0.2% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 120,306 | $763K | 0.2% | 2026-Q2 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC added | 110,000 | $697K | 0.2% | 2026-Q2 |
| Mitsubishi UFJ Asset Management Co., Ltd. trimmed | 107,505 | $682K | 0.1% | 2026-Q2 |
| Sargent Investment Group, LLC trimmed | 106,432 | $675K | 0.1% | 2026-Q2 |
| Inspire Investing, LLC trimmed | 106,330 | $674K | 0.1% | 2026-Q2 |
| IEQ CAPITAL, LLC new | 103,313 | $655K | 0.1% | 2026-Q2 |
| RBF Capital, LLC | 100,000 | $634K | 0.1% | 2026-Q2 |
| Man Group plc trimmed | 90,259 | $572K | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS trimmed | 83,335 | $528K | 0.1% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. added | 74,130 | $254K | 0.1% | 2026-Q2 |
| LPL Financial LLC added | 69,365 | $440K | 0.1% | 2026-Q2 |
| FMR LLC added | 68,476 | $434K | 0.1% | 2026-Q2 |
| EntryPoint Capital, LLC trimmed | 67,794 | $430K | 0.1% | 2026-Q2 |
| UBS Group AG trimmed | 66,671 | $423K | 0.1% | 2026-Q2 |
| OPPENHEIMER & CO INC trimmed | 64,430 | $408K | 0.1% | 2026-Q2 |
| WINTON GROUP Ltd added | 61,200 | $388K | 0.1% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 59,370 | $376K | 0.1% | 2026-Q2 |
| Centiva Capital, LP added | 56,459 | $358K | 0.1% | 2026-Q2 |
| FRANKLIN RESOURCES INC trimmed | 47,907 | $304K | 0.1% | 2026-Q2 |
| Graham Capital Management, L.P. trimmed | 46,267 | $293K | 0.1% | 2026-Q2 |
| Arax Advisory Partners added | 46,153 | $293K | 0.1% | 2026-Q2 |
| Quantbot Technologies LP added | 45,432 | $288K | 0.1% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 43,717 | $277K | 0.1% | 2026-Q2 |
| Mariner, LLC added | 42,652 | $270K | 0.1% | 2026-Q2 |
| Odyssean, LLC | 41,759 | $265K | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC added | 40,269 | $255K | 0.1% | 2026-Q2 |
| MERCER GLOBAL ADVISORS INC /ADV new | 38,679 | $245K | 0.1% | 2026-Q2 |
| State of Wyoming new | 38,000 | $241K | 0.1% | 2026-Q2 |
| FOX RUN MANAGEMENT, L.L.C. added | 37,919 | $240K | 0.1% | 2026-Q2 |
| Y-Intercept (Hong Kong) Ltd trimmed | 36,820 | $233K | 0.1% | 2026-Q2 |
| Dynamic Technology Lab Private Ltd trimmed | 35,103 | $223K | 0.0% | 2026-Q2 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 33,247 | $211K | 0.0% | 2026-Q2 |
| DIVERSIFIED TRUST CO new | 33,047 | $210K | 0.0% | 2026-Q2 |
| Concurrent Investment Advisors, LLC added | 32,050 | $203K | 0.0% | 2026-Q2 |
| Creative Planning added | 31,432 | $199K | 0.0% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. trimmed | 31,271 | $198K | 0.0% | 2026-Q2 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC added | 30,386 | $157K | 0.0% | 2026-Q2 |
| BAILARD, INC. new | 29,508 | $187K | 0.0% | 2026-Q2 |
| Vanguard Global Advisers, LLC | 28,581 | $181K | 0.0% | 2026-Q2 |
| Cerity Partners LLC added | 28,365 | $180K | 0.0% | 2026-Q2 |
| Headlands Technologies LLC new | 27,413 | $174K | 0.0% | 2026-Q2 |
| nVerses Capital, LLC trimmed | 25,234 | $160K | 0.0% | 2026-Q2 |
| INTECH INVESTMENT MANAGEMENT LLC added | 21,535 | $137K | 0.0% | 2026-Q2 |
| CANADA PENSION PLAN INVESTMENT BOARD trimmed | 20,700 | $131K | 0.0% | 2026-Q2 |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.