Aspen Aerogels (ASPN)
Aspen Aerogels on one page: short interest, daily short volume, fails to deliver, planned sales, large holders, 13F holders, earnings dates and insider trades. Listed on NYSE, classified by the SEC as wholesale-lumber & other construction materials.
6.1M
Short interest
settlement 2026-09-30
5.2
Days to cover
-8.7 days vs prior
42.7%
Short share of volume
2026-10-09
962
Fails to deliver
settlement 2026-09-14
Thu 5 Nov
Next earnings
estimated date
-$58.1M
Insider flow, 90 days
0 buys, 1 sells
As of 2026-10-09.
Short interest
FINRA, twice a month. The newest 24 settlements in the table, 48 in the chart. JSONAs of 30 September 2026, short interest in ASPN is 6,101,632 shares, down 2,302,109 shares over the last month. Over the last 48 readings it ranged from 6,101,632 shares (30 September 2026) to 11,466,276 shares (14 February 2025). The latest reading sits at the bottom of that range. At the reported average volume of 1.2M shares a day that is 5.2 days to cover.
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| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| 2026-09-30 | 6,101,632 | -32.7% | 1,164,371 | 5.24 |
| 2026-09-15 | 9,064,528 | +7.9% | 650,743 | 13.93 |
| 2026-08-31 | 8,403,741 | +3.9% | 771,420 | 10.89 |
| 2026-08-14 | 8,084,832 | -8.6% | 2,513,475 | 3.22 |
| 2026-07-31 | 8,849,264 | +7.6% | 988,038 | 8.96 |
| 2026-07-15 | 8,223,398 | +15.8% | 978,232 | 8.41 |
| 2026-06-30 | 7,102,074 | -0.1% | 1,887,633 | 3.76 |
| 2026-06-15 | 7,110,861 | +0.3% | 1,229,390 | 5.78 |
| 2026-05-29 | 7,089,306 | -8.4% | 1,534,207 | 4.62 |
| 2026-05-15 | 7,736,011 | -3.3% | 2,477,242 | 3.12 |
| 2026-04-30 | 7,999,553 | +14.0% | 1,592,856 | 5.02 |
| 2026-04-15 | 7,017,875 | +12.6% | 1,335,401 | 5.26 |
| 2026-03-31 | 6,232,371 | -11.7% | 1,170,117 | 5.33 |
| 2026-03-13 | 7,054,834 | -5.3% | 1,579,655 | 4.47 |
| 2026-02-27 | 7,449,281 | +0.2% | 2,452,316 | 3.04 |
| 2026-02-13 | 7,432,237 | -2.2% | 1,172,470 | 6.34 |
| 2026-01-30 | 7,597,323 | -13.0% | 1,562,950 | 4.86 |
| 2026-01-15 | 8,730,143 | -4.6% | 1,583,588 | 5.51 |
| 2025-12-31 | 9,150,305 | +9.2% | 2,284,399 | 4.01 |
| 2025-12-15 | 8,377,032 | -2.2% | 1,731,123 | 4.84 |
| 2025-11-28 | 8,561,660 | -11.5% | 2,198,480 | 3.89 |
| 2025-11-14 | 9,669,850 | +13.2% | 4,812,003 | 2.01 |
| 2025-10-31 | 8,544,699 | -0.4% | 1,771,318 | 4.82 |
| 2025-10-15 | 8,579,892 | -16.6% | 2,313,675 | 3.71 |
Daily short volume
FINRA Reg SHO, the last 30 sessions. JSONAs of 9 October 2026, the short share of ASPN volume is 42.7%, up 4.2 points over the last five sessions. Over the last 30 readings it ranged from 31.2% (25 September 2026) to 61.4% (22 September 2026). The latest reading is 2.9 points below the 30-session average of 45.7%, on 160K shares reported.
| Date | Short volume | Total volume | Short share | Exempt |
|---|---|---|---|---|
| 2026-10-09 | 68K | 160K | 42.7% | 0 |
| 2026-10-08 | 72K | 178K | 40.7% | 632 |
| 2026-10-07 | 102K | 230K | 44.4% | 18 |
| 2026-10-06 | 95K | 197K | 48.2% | 0 |
| 2026-10-05 | 92K | 221K | 41.7% | 744 |
| 2026-10-02 | 99K | 256K | 38.6% | 0 |
| 2026-10-01 | 88K | 234K | 37.4% | 0 |
| 2026-09-30 | 160K | 281K | 57.0% | 0 |
| 2026-09-29 | 119K | 219K | 54.2% | 0 |
| 2026-09-28 | 141K | 302K | 46.7% | 25 |
| 2026-09-25 | 221K | 708K | 31.2% | 0 |
| 2026-09-24 | 287K | 815K | 35.2% | 0 |
| 2026-09-23 | 179K | 355K | 50.4% | 0 |
| 2026-09-22 | 270K | 439K | 61.4% | 3,000 |
| 2026-09-21 | 106K | 229K | 46.1% | 580 |
| 2026-09-18 | 65K | 126K | 51.4% | 0 |
| 2026-09-17 | 75K | 181K | 41.3% | 2,011 |
| 2026-09-16 | 69K | 172K | 40.4% | 981 |
| 2026-09-15 | 65K | 151K | 42.8% | 6 |
| 2026-09-14 | 72K | 167K | 43.2% | 147 |
| 2026-09-11 | 100K | 199K | 50.2% | 1,705 |
| 2026-09-10 | 79K | 165K | 47.7% | 0 |
| 2026-09-09 | 135K | 271K | 49.9% | 4 |
| 2026-09-08 | 90K | 192K | 46.7% | 5,631 |
| 2026-09-04 | 50K | 123K | 40.9% | 0 |
| 2026-09-03 | 122K | 266K | 45.9% | 28 |
| 2026-09-02 | 101K | 208K | 48.8% | 0 |
| 2026-09-01 | 172K | 346K | 49.8% | 1,282 |
| 2026-08-31 | 129K | 244K | 53.0% | 0 |
| 2026-08-28 | 120K | 287K | 41.7% | 31 |
Fails to deliver
SEC, the last 30 settlement dates with a fail. JSONAs of 14 September 2026, the fails-to-deliver balance in ASPN is 962 shares, up 764 shares over the last settlement date. Over the last 30 readings it ranged from 12 shares (2 April 2026) to 59,814 shares (12 February 2026). The latest reading sits at the bottom of that range.
| Settlement | Shares failed | Price | Value |
|---|---|---|---|
| 2026-09-14 | 962 | $4.91 | $5K |
| 2026-08-11 | 198 | $6.29 | $1K |
| 2026-08-07 | 18,393 | $6.89 | $127K |
| 2026-08-06 | 4,378 | $5.01 | $22K |
| 2026-08-05 | 25,802 | $5.06 | $131K |
| 2026-08-03 | 1,552 | $4.63 | $7K |
| 2026-06-26 | 3,877 | $5.68 | $22K |
| 2026-06-24 | 3,480 | $5.90 | $21K |
| 2026-06-16 | 3,171 | $6.04 | $19K |
| 2026-06-15 | 622 | $5.92 | $4K |
| 2026-06-03 | 15,052 | $6.22 | $94K |
| 2026-06-01 | 1,487 | $6.40 | $10K |
| 2026-05-08 | 26,852 | $5.12 | $137K |
| 2026-05-06 | 4,395 | $4.14 | $18K |
| 2026-04-30 | 79 | $3.61 | $285 |
| 2026-04-21 | 37 | $3.56 | $132 |
| 2026-04-09 | 796 | $3.71 | $3K |
| 2026-04-02 | 12 | $3.47 | $42 |
| 2026-03-27 | 23 | $3.42 | $79 |
| 2026-03-16 | 58 | $3.65 | $212 |
| 2026-03-11 | 1,457 | $3.25 | $5K |
| 2026-02-12 | 59,814 | $3.51 | $210K |
| 2026-02-05 | 1,013 | $3.29 | $3K |
| 2026-01-16 | 707 | $3.45 | $2K |
| 2026-01-12 | 51,702 | $3.30 | $171K |
| 2026-01-08 | 1,483 | $3.24 | $5K |
| 2026-01-07 | 2,500 | $3.33 | $8K |
| 2026-01-05 | 84 | $2.89 | $243 |
| 2025-12-31 | 1,578 | $2.95 | $5K |
| 2025-12-17 | 457 | $3.08 | $1K |
Insider trades
SEC Form 4, newest first, 50 of 100 shown. JSONInsiders at ASPN reported 1 open-market sell worth $58.1M in the last 90 days and no open-market buys. Latest filing: DEEGAN GLENN E. (CAO, GC & Corp Secretary) on 2026-09-30.
| Date | Insider | Title | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|---|
| 2026-09-30 | DEEGAN GLENN E. | CAO, GC & Corp Secretary | Tax withholding | 1K | $5.48 | $6K | 66K |
| 2026-09-23 | Wood River Capital, LLC | Former 10% Owner | Sell | 12.3M | $4.73 | $58.1M | 0 |
| 2026-06-23 | NOGLOWS WILLIAM P | Director | Option exercise | 15K | $4.75 | $70K | 114K |
| 2026-05-13 | Mitchell Steven R | Director | Grant | 10K | $0.00 | $0 | 157K |
| 2026-05-13 | SWEETNAM JAMES E | Director | Grant | 10K | $0.00 | $0 | 36K |
| 2026-05-13 | NOGLOWS WILLIAM P | Director | Grant | 10K | $0.00 | $0 | 99K |
| 2026-05-13 | Kool Kathleen | Director | Grant | 10K | $0.00 | $0 | 34K |
| 2026-05-13 | Robinson Cari | Director | Grant | 10K | $0.00 | $0 | 23K |
| 2026-03-08 | Young Donald R | President and CEO | Tax withholding | 4K | $3.22 | $14K | 638K |
| 2026-03-08 | Whitaker Corby C | Chief Commercial Officer | Tax withholding | 2K | $3.22 | $6K | 205K |
| 2026-03-08 | Thoele Grant Douglas | CFO & Treasurer | Tax withholding | 590 | $3.22 | $2K | 78K |
| 2026-03-08 | Landes Gregg | Chief Operating Officer | Tax withholding | 2K | $3.22 | $6K | 103K |
| 2026-03-05 | Young Donald R | President and CEO | Tax withholding | 9K | $3.27 | $28K | 642K |
| 2026-03-05 | Landes Gregg | SVP, Operations and Strat Deve | Tax withholding | 4K | $3.27 | $12K | 105K |
| 2026-03-05 | Whitaker Corby C | SVP, Sales and Marketing | Tax withholding | 4K | $3.27 | $13K | 207K |
| 2026-03-05 | Daniel Santhosh P | Chief Accounting Officer | Tax withholding | 986 | $3.27 | $3K | 15K |
| 2026-03-05 | Thoele Grant Douglas | CFO & Treasurer | Tax withholding | 2K | $3.27 | $8K | 78K |
| 2026-03-04 | Young Donald R | President and CEO | Grant | 157K | $0.00 | $0 | 651K |
| 2026-03-04 | Landes Gregg | SVP, Operations and Strat Deve | Grant | 57K | $0.00 | $0 | 109K |
| 2026-03-04 | DEEGAN GLENN E. | CAO, GC & Corp Secretary | Grant | 56K | $0.00 | $0 | 67K |
| 2026-03-04 | Whitaker Corby C | SVP, Sales and Marketing | Grant | 57K | $0.00 | $0 | 211K |
| 2026-03-04 | Thoele Grant Douglas | CFO & Treasurer | Grant | 55K | $0.00 | $0 | 81K |
| 2025-11-13 | Young Donald R | President and CEO | Sell | 57K | $3.23 | $184K | 494K |
| 2025-10-01 | Thoele Grant Douglas | CFO & Treasurer | Grant | 10K | $0.00 | $0 | 25K |
| 2025-10-01 | Thoele Grant Douglas | CFO & Treasurer | Grant | 10K | $0.00 | $0 | 15K |
| 2025-09-30 | DEEGAN GLENN E. | CAO, GC & Corp Secretary | Grant | 12K | $0.00 | $0 | 12K |
| 2025-09-13 | Daniel Santhosh P | Chief Accounting Officer | Tax withholding | 2K | $6.59 | $10K | 16K |
| 2025-09-05 | Pittman Stephanie | Chief Human Resources Officer | Tax withholding | 2K | $6.61 | $10K | 42K |
| 2025-08-13 | Daniel Santhosh P | Chief Accounting Officer | Sell | 2K | $7.54 | $15K | 18K |
| 2025-08-12 | Daniel Santhosh P | Chief Accounting Officer | Sell | 4K | $7.31 | $32K | 20K |
| 2025-05-23 | Johnson Virginia | CLO, GC, and Secretary | Tax withholding | 6K | $6.39 | $39K | 44K |
| 2025-05-12 | Young Donald R | President and CEO | Buy | 20K | $5.35 | $107K | 551K |
| 2025-04-30 | NOGLOWS WILLIAM P | Director | Grant | 10K | $0.00 | $0 | 89K |
| 2025-04-30 | Kool Kathleen | Director | Grant | 10K | $0.00 | $0 | 24K |
| 2025-04-30 | Robinson Cari | Director | Grant | 10K | $0.00 | $0 | 12K |
| 2025-04-30 | SWEETNAM JAMES E | Director | Grant | 10K | $0.00 | $0 | 26K |
| 2025-04-30 | Mitchell Steven R | Director | Grant | 10K | $0.00 | $0 | 147K |
| 2025-03-07 | Landes Gregg | SVP, Operations and Strat Deve | Tax withholding | 2K | $7.95 | $15K | 51K |
| 2025-03-07 | RODRIGUEZ RICARDO C. | CFO & Treasurer | Tax withholding | 2K | $7.95 | $15K | 57K |
| 2025-03-07 | Whitaker Corby C | SVP, Sales and Marketing | Tax withholding | 2K | $7.95 | $15K | 154K |
| 2025-03-07 | SCHILLING KEITH L | SVP, Technology | Tax withholding | 2K | $7.95 | $15K | 50K |
| 2025-03-07 | Young Donald R | President and CEO | Tax withholding | 4K | $7.95 | $28K | 531K |
| 2025-03-07 | Johnson Virginia | CLO, GC, and Secretary | Tax withholding | 2K | $7.95 | $15K | 51K |
| 2025-03-05 | Pittman Stephanie | Chief Human Resources Officer | Grant | 22K | $0.00 | $0 | 44K |
| 2025-03-05 | Pittman Stephanie | Chief Human Resources Officer | Tax withholding | 936 | $7.84 | $7K | 22K |
| 2025-03-05 | Whitaker Corby C | SVP, Sales and Marketing | Grant | 26K | $0.00 | $0 | 156K |
| 2025-03-05 | Whitaker Corby C | SVP, Sales and Marketing | Tax withholding | 936 | $7.84 | $7K | 130K |
| 2025-03-05 | SCHILLING KEITH L | SVP, Technology | Tax withholding | 936 | $7.84 | $7K | 27K |
| 2025-03-05 | SCHILLING KEITH L | SVP, Technology | Grant | 25K | $0.00 | $0 | 52K |
| 2025-03-05 | Young Donald R | President and CEO | Grant | 54K | $0.00 | $0 | 534K |
Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are rarer.
Planned sales (Form 144)
Newest first. JSON2 Form 144 notices on file for ASPN worth $230K at the prices reported; 1 in the last 90 days worth $35K. Latest: SANTHOSH P DANIEL filed on 2026-08-10 to sell 5,593 shares ($35K) from 2026-08-10.
| Filed | Seller | Shares | Market value | Of outstanding | Sale from | Broker |
|---|---|---|---|---|---|---|
| 2026-08-10 | SANTHOSH P DANIELOfficer | 6K | $35K | 0.007% | 2026-08-10 | Morgan Stanley Smith Barney LLC Executive Financial Services |
| 2025-11-13 | DONALD YOUNGDirector, Officer | 57K | $195K | 0.069% | 2025-11-13 | Morgan Stanley Smith Barney LLC Executive Financial Services |
Large holders (13D and 13G)
One row per reporting person with its latest filing, newest first. JSONNo holder on file reports 5% or more of ASPN in its latest filing.
| Filed | Form | Holder | Shares | Of class | Event |
|---|---|---|---|---|---|
| 2026-09-24 | 13D/Ano. 6 | Koch, Inc.corporation | 0 | 0.0% | 2026-09-23 |
| 2026-09-24 | 13D/Ano. 6 | Wood River Capital, LLCother entity | 0 | 0.0% | 2026-09-23 |
| 2026-08-13 | 13G/Ano. 1 | Needham Investment Management L.L.C.investment adviser, other entity | 3.3M | 3.9% | 2026-06-30 |
| 2026-08-13 | 13G/Ano. 1 | Needham Asset Management, LLCparent holding company, other entity | 3.3M | 3.9% | 2026-06-30 |
| 2026-08-13 | 13G/Ano. 1 | George A. Needhamparent holding company, individual | 3.3M | 3.9% | 2026-06-30 |
| 2026-03-26 | 13G/Ano. 2 | The Vanguard Groupinvestment adviser | 0 | 0.0% | 2026-03-13 |
13F holders
Tracked managers holding ASPN at their latest 13F. JSON7 of the 30 tracked managers held ASPN at their latest 13F, $30.7M in total at quarter-end prices. AQR Capital Management is the largest at $8.1M (0.0% of its portfolio) as of 2026-06-30. Over the prior quarter 4 added shares and 3 cut.
| Fund | Quarter | Shares | Value | Of portfolio | Change in shares |
|---|---|---|---|---|---|
| AQR Capital Management | 2026-06-30 | 1.3M | $8.1M | 0.00% | +750K |
| Millennium Management | 2026-06-30 | 1.2M | $7.5M | 0.00% | -214K |
| D. E. Shaw & Co. | 2026-06-30 | 1.1M | $6.8M | 0.00% | +233K |
| Two Sigma Investments | 2026-06-30 | 779K | $4.9M | 0.00% | +338K |
| Renaissance Technologies | 2026-06-30 | 274K | $1.7M | 0.00% | new |
| Citadel Advisors | 2026-06-30 | 239K | $1.5M | 0.00% | -342K |
| Point72 Asset Management | 2026-06-30 | 9K | $57K | 0.00% | -248K |
Only the 30 tracked managers on the funds hub; a 13F reports long positions in US listed stock at quarter end, 45 days late, and says nothing about shorts or positions sold since.
What this page is
Aspen Aerogels in the regulatory record
Regulators publish company data in separate files that never sit next to each other: FINRA's twice-monthly short interest, its daily short sale volume, the SEC's fails-to-deliver counts, and each insider's Form 4. A company page puts those series for one ticker on one URL, with planned sales, large holders, 13F holders and financials beside them, so the short position, the daily flow, the settlement fails and what insiders are doing can be read together.
Each section has its own history table, a one-line summary of the latest figures and its own JSON and CSV links, and says when its source last updated.
This page follows Aspen Aerogels (ASPN), SEC CIK 1145986, listed on NYSE, classified by the SEC as wholesale-lumber & other construction materials. The cross-market tables live on the short interest and insider transactions hubs.
Source and updates
- Short interest
- FINRA consolidated short interestSource: FINRA.Twice a month, about eight business days after settlement. Latest 2026-09-30.JSON and CSV
- Daily short volume
- FINRA Reg SHO daily filesSource: FINRA.Every trading day, the morning after FINRA posts it. Latest 2026-10-09.JSON and CSV
- Fails to deliver
- SEC fails-to-deliver dataSource: SEC.Twice a month, a few weeks after the half month ends. Latest 2026-09-14.JSON and CSV
- Planned sales
- SEC EDGAR Form 144Source: SEC.New notices appear shortly after the SEC posts them; a notice is filed on or before the sale. Latest 2026-08-10.JSON and CSV
- Large holders
- SEC EDGAR Schedule 13D and 13GSource: SEC.New filings appear shortly after the SEC posts them. A 13D is due within five business days of crossing 5%; a 13G follows the passive schedule. Latest 2026-09-24.JSON and CSV
- 13F holders
- SEC EDGAR Form 13F-HRSource: SEC.Quarterly, filed within 45 days of quarter end; 30 tracked managers. Latest 2026-06-30.JSON and CSV
- Earnings dates
- SEC EDGAR 8-K filings (Item 2.02)Source: SEC.Twice a day. Reported dates come from the company's 8-K filings; the next date is marked as an estimate until the 8-K arrives. Latest 2026-08-06.JSON and CSV
- Insider trades
- SEC EDGAR Form 4Source: SEC.New filings appear shortly after the SEC posts them; they're due two business days after the trade. Latest 2026-09-30.JSON and CSV
- Company record
- EDGAR filing index for CIK 1145986Ticker, name and exchange from the SEC's company list, refreshed weekly.
- Rate limits
- 10 requests a minute without a key, 30 with a free key from a free account.
How to read it
- Read the position against the flow: rising short interest with a high daily short share is new shorting; rising short interest with a normal short share is old shorts holding on.
- Insider buys next to a large short position are rare and stand out; insider sells next to one are common and mean little.
- Fails to deliver matter relative to the float, not in absolute shares; a million failed shares in a mega cap is noise.
Analysis of what the data shows, not advice. XOOMAR does not recommend buying, selling or holding anything.
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Datasets
Frequently Asked Questions
How much of ASPN is sold short?
What is ASPN's daily short volume?
Does ASPN have fails to deliver?
Are ASPN insiders buying or selling?
Have ASPN insiders filed to sell?
Who owns 5% or more of ASPN?
Which tracked 13F managers own ASPN?
Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.