ASPINasdaqMiscellaneous Chemical ProductsFiscal year ends December 31
ASP Isotopes Inc.
Financials through Q2 FY2026, quarter ended Jun 30, 2026Last filing: 10-Q on Aug 14, 2026
$2.06−0.08 (-3.97%)
Close on Oct 19, 2026
- Market cap
- $252.18M
- P/E (TTM)
- –
- Dividend yield
- –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
42.7%
65M of 153M shares
Institutional holders
185
40 new, 28 sold out
Net institutional buying
1M
In Q2 2026
Insider trades, 12 months
1 buys · 28 sales
Net sold $9.41M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| BlackRock, Inc. | 8,274,763 | 6.60% | 13G (passive) amendment | Mar 31, 2026 |
| Mann Paul Elliot | 7,759,538 | 7.00% | 13G (passive) amendment | Dec 31, 2025 |
| Todd J. Kantor | 6,413,362 | 5.13% | 13G (passive) | Jan 16, 2026 |
| AWM Investment Company, Inc. | 619,874 | 6.90% | 13G (passive) | Jun 30, 2025 |
| AK Jensen Investment Management Ltd | 4,955,261 | 5.40% | 13G (passive) amendment | Sep 30, 2025 |
| AK Jensen Investment Management Limited | 4,708,551 | 6.60% | 13G (passive) amendment | Dec 31, 2024 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of ASPI | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| BlackRock, Inc. | 9,217,198 | 6.01% | $57.33M | +889,054 | 0.00% |
| Encompass Capital Advisors LLC | 6,561,754 | 4.28% | $40.81M | −350,300 | 1.45% |
| Vanguard Capital Management LLC | 4,982,953 | 3.25% | $30.99M | −77,511 | 0.00% |
| Rovida Investment Management Ltd | 4,100,000 | 2.67% | $25.50M | – | 1.74% |
| UBS Group AG | 3,247,633 | 2.12% | $20.20M | +405,924 | 0.00% |
| Geode Capital Management, LLC | 2,945,901 | 1.92% | $18.33M | +205,437 | 0.00% |
| Alyeska Investment Group, L.P. | 2,843,503 | 1.85% | $17.69M | +151,337 | 0.05% |
| State Street Corp | 2,595,573 | 1.69% | $16.14M | +273,414 | 0.00% |
| Exchange Traded Concepts, LLC | 2,255,509 | 1.47% | $14.03M | +71,955 | 0.06% |
| AWM Investment Company, Inc. | 1,581,490 | 1.03% | $9.84M | −543,006 | 0.85% |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. | 1,577,016 | 1.03% | $9.81M | +689,771 | 0.01% |
| Philadelphia Financial Management of San Francisco, LLC | 1,343,007 | 0.88% | $8.35M | +694,666 | 1.68% |
| Morgan Stanley | 1,162,320 | 0.76% | $7.23M | −414,093 | 0.00% |
| Vanguard Portfolio Management LLC | 1,115,391 | 0.73% | $6.94M | +138,221 | 0.00% |
| Northern Trust Corp | 1,007,214 | 0.66% | $6.26M | +69,691 | 0.00% |
| Charles Schwab Investment Management Inc | 935,352 | 0.61% | $5.82M | +38,116 | 0.00% |
| Barclays PLC | 847,781 | 0.55% | $5.27M | −165,175 | 0.00% |
| Marshall Wace, Llp | 835,656 | 0.55% | $5.20M | New | 0.00% |
| Man Group plc | 828,377 | 0.54% | $5.15M | New | 0.01% |
| Vanguard Fiduciary Trust Co | 788,561 | 0.51% | $4.90M | +35,245 | 0.00% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 185 | 65M | 42.7% | 40 / 74 | 51 / 28 | 9M | 8M |
| Q1 2026 | 177 | 64M | 41.9% | 42 / 78 | 40 / 33 | 23M | 11M |
| Q4 2025 | 173 | 59M | 38.5% | 49 / 77 | 35 / 31 | 21M | 15M |
| Q3 2025 | 157 | 53M | 34.8% | 45 / 70 | 31 / 17 | 19M | 8M |
| Q2 2025 | 130 | 42M | 27.1% | 44 / 49 | 25 / 13 | 14M | 5M |
| Q1 2025 | 100 | 33M | 21.3% | 20 / 39 | 24 / 13 | 5M | 5M |
| Q4 2024 | 95 | 33M | 21.2% | 37 / 34 | 18 / 10 | 13M | 3M |
| Q3 2024 | 69 | 22M | 14.6% | 26 / 32 | 7 / 7 | 16M | 0M |
| Q2 2024 | 51 | 9M | 5.7% | 31 / 11 | 9 / 11 | 6M | 1M |
| Q1 2024 | 31 | 4M | 2.6% | 16 / 12 | 3 / 4 | 3M | 1M |
| Q4 2023 | 19 | 2M | 1.1% | 10 / 6 | 3 / 2 | 1M | 0M |
| Q3 2023 | 11 | 0M | 0.2% | 8 / 0 | 3 / 1 | 0M | 0M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
| Fund | Shares | % of ASPI | Value | % of fund | As of |
|---|---|---|---|---|---|
| Vanguard Total Stock Market Index Fund | 3,593,895 | 2.34% | $22.35M | 0.00% | Jun 30, 2026 |
| iShares Russell 2000 ETF | 3,041,965 | 1.98% | $18.92M | 0.02% | Jun 30, 2026 |
| Range Nuclear Renaissance Index ETF | 2,266,579 | 1.48% | $17.63M | 1.98% | May 31, 2026 |
| Fidelity Small Cap Index Fund | 1,275,240 | 0.83% | $5.10M | 0.01% | Jul 31, 2026 |
| Vanguard Extended Market Index Fund | 1,255,393 | 0.82% | $7.81M | 0.01% | Jun 30, 2026 |
| iShares Russell 2000 Growth ETF | 903,929 | 0.59% | $5.62M | 0.04% | Jun 30, 2026 |
| American Beacon GLG Natural Resources ETF | 839,371 | 0.55% | $3.36M | 0.40% | Jul 31, 2026 |
| Pacer Data & Infrastructure Real Estate ETF | 738,035 | 0.48% | $2.95M | 0.80% | Jul 31, 2026 |
| Vanguard Russell 2000 Index Fund | 584,502 | 0.38% | $4.55M | 0.03% | May 31, 2026 |
| Fidelity Extended Market Index Fund | 571,961 | 0.37% | $4.45M | 0.01% | May 31, 2026 |
| Schwab U.S. Small-Cap ETF | 537,784 | 0.35% | $4.18M | 0.02% | May 31, 2026 |
| iShares Micro-Cap ETF | 391,459 | 0.26% | $2.43M | 0.16% | Jun 30, 2026 |
| Vanguard Materials Index Fund | 308,858 | 0.20% | $2.40M | 0.05% | May 31, 2026 |
| Schwab Small-Cap Index Fund | 277,199 | 0.18% | $1.11M | 0.01% | Jul 31, 2026 |
| Nuveen Equity Index Fund | 275,656 | 0.18% | $1.10M | 0.00% | Jul 31, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| Paul Elliot Mann | Chairman and CEO, Director | 9,328,570 | 6.08% | Sep 4, 2026 |
| Robert Ainscow | COO | 2,248,441 | 1.47% | Sep 10, 2026 |
| Donald George Ainscow | EVP, Gen Counsel, Secretary | 776,322 | 0.51% | Sep 4, 2026 |
| Heather Kiessling | Chief Financial Officer | 1,526,252 | 1.00% | Jul 2, 2026 |
| Robert John Andrew Ryan | Director | 660,222 | 0.43% | Sep 30, 2026 |
| Todd Wider | Director | 672,247 | 0.44% | Jul 1, 2026 |
| Michael Gorley | Director | 87,908 | 0.06% | Jul 1, 2026 |
| Duncan Moore | Director | 1,044,928 | 0.68% | Apr 17, 2026 |
| Ralph L. Hunter JR | Director | 47,018 | 0.03% | Dec 22, 2025 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Robert John Andrew Ryan Director | Sep 28, 2026 | Buy | +8,000 | $2.70 | $21.60K | 660,222 |
| Robert Ainscow COO | Sep 8, 2026 | Sale(10b5-1 plan) | −8,438 | $4.29 | $36.20K | 2,248,441 |
| Paul Elliot Mann Chairman and CEO, Director | Sep 4, 2026 | Sale(10b5-1 plan) | −83,759 | $4.10 | $343.41K | 9,328,570 |
| Paul Elliot Mann Chairman and CEO, Director | Sep 3, 2026 | Sale(10b5-1 plan) | −83,758 | $3.92 | $328.33K | 9,412,329 |
| Paul Elliot Mann Chairman and CEO, Director | Sep 2, 2026 | Sale(10b5-1 plan) | −83,758 | $3.91 | $327.49K | 9,496,087 |
| Robert Ainscow COO | Sep 2, 2026 | Sale(10b5-1 plan) | −25,000 | $3.91 | $97.75K | 2,256,879 |
| Donald George Ainscow EVP, Gen Counsel, Secretary | Sep 2, 2026 | Sale | −23,678 | $3.89 | $92.11K | 776,322 |
| Heather Kiessling Chief Financial Officer | Jul 1, 2026 | Sale(10b5-1 plan) | −23,124 | $6.28 | $145.22K | 1,526,252 |
| Donald George Ainscow EVP, Gen Counsel, Secretary | Jun 30, 2026 | Sale | −100,000 | $6.14 | $614.00K | 800,000 |
| Michael Gorley Director | Jun 30, 2026 | Sale | −30,000 | $6.27 | $188.10K | 87,908 |
| Todd Wider Director | Jun 30, 2026 | Sale | −50,000 | $6.12 | $306.00K | 672,247 |
| Todd Wider Director | Jun 29, 2026 | Sale | −50,000 | $6.25 | $312.50K | 722,247 |
| Robert Ainscow COO | Jun 8, 2026 | Sale(10b5-1 plan) | −8,438 | $7.00 | $59.07K | 2,281,879 |
| Paul Elliot Mann Chairman and CEO, Director | Jun 3, 2026 | Sale(10b5-1 plan) | −83,759 | $7.76 | $649.97K | 9,579,845 |
| Paul Elliot Mann Chairman and CEO, Director | Jun 2, 2026 | Sale(10b5-1 plan) | −83,758 | $8.29 | $694.35K | 9,663,424 |
| Paul Elliot Mann Chairman and CEO, Director | Jun 1, 2026 | Sale(10b5-1 plan) | −83,758 | $7.88 | $660.01K | 9,747,182 |
| Heather Kiessling Chief Financial Officer | May 28, 2026 | Award | +840,000 | – | – | 1,549,376 |
| Paul Elliot Mann Chairman and CEO, Director | May 28, 2026 | Award | +2,233,555 | – | – | 9,830,940 |
| Robert Ainscow Chief Operating Officer | May 28, 2026 | Award | +800,000 | – | – | 2,290,317 |
| Donald George Ainscow EVP, Gen Counsel, Secretary | May 28, 2026 | Award | +400,000 | – | – | 900,000 |
| Robert Ainscow COO | Apr 16, 2026 | Sale(10b5-1 plan) | −22,500 | $5.21 | $117.23K | 1,490,317 |
| Duncan Moore Director | Apr 16, 2026 | Sale(10b5-1 plan) | −11,642 | $5.21 | $60.65K | 1,044,928 |
| Heather Kiessling Chief Financial Officer | Apr 15, 2026 | Sale(10b5-1 plan) | −23,124 | $5.48 | $126.72K | 709,376 |
| Robert Ainscow COO | Mar 6, 2026 | Sale(10b5-1 plan) | −25,000 | $4.51 | $112.75K | 1,512,817 |
| Robert Ainscow COO | Mar 6, 2026 | Sale(10b5-1 plan) | −8,438 | $5.44 | $45.90K | 1,537,817 |
| Paul Elliot Mann Executive Chairman | Mar 2, 2026 | Sale(10b5-1 plan) | +162,153 | $5.44 | $882.11K | 7,597,385 |
| Duncan Moore Director | Dec 18, 2025 | Award | +36,548 | – | – | 1,056,570 |
| Heather Kiessling Chief Financial Officer | Dec 18, 2025 | Sale | −80,000 | $5.80 | $464.00K | 732,500 |
| Ralph L. Hunter JR Director | Dec 18, 2025 | Award | +36,548 | – | – | 47,018 |
| Robert John Andrew Ryan Director | Dec 18, 2025 | Award | +36,548 | – | – | 652,222 |
| Michael Gorley Director | Dec 18, 2025 | Award | +36,548 | – | – | 117,908 |
| Todd Wider Director | Dec 18, 2025 | Award | +36,548 | – | – | 772,247 |
| Robert Ainscow Interim CEO and COO | Dec 8, 2025 | Sale(10b5-1 plan) | −8,438 | $6.20 | $52.32K | 1,546,255 |
| Paul Elliot Mann Executive Chairman, Director | Dec 1, 2025 | Sale(10b5-1 plan) | −162,153 | $5.75 | $932.38K | 7,759,538 |
| Paul Elliot Mann Executive Officer, Director | Nov 25, 2025 | Sale(10b5-1 plan) | −50,000 | $5.77 | $288.50K | 7,921,691 |
| Robert Ainscow Interim CEO and COO | Nov 25, 2025 | Sale(10b5-1 plan) | −25,000 | $5.77 | $144.25K | 1,554,693 |
| Paul Elliot Mann Executive Officer, Director | Nov 17, 2025 | Sale(10b5-1 plan) | −112,500 | $7.51 | $844.88K | 7,971,691 |
| Robert Ainscow Interim CEO and COO | Nov 17, 2025 | Sale(10b5-1 plan) | −67,500 | $7.51 | $506.93K | 1,579,693 |
| Duncan Moore Director | Nov 12, 2025 | Award | +25,469 | – | – | 1,020,022 |
| Todd Wider Director | Nov 12, 2025 | Award | +25,469 | – | – | 735,699 |
| Robert Ainscow Interim CEO and COO | Oct 14, 2025 | Sale(10b5-1 plan) | −22,500 | $13.60 | $306.00K | 1,647,193 |
| Michael Gorley Director | Sep 30, 2025 | Sale | −64,000 | $9.75 | $624.00K | 81,360 |
| Todd Wider Director | Sep 15, 2025 | Sale | −74,108 | $8.76 | $649.19K | 710,230 |
| Todd Wider Director | Sep 14, 2025 | Option exercise | +96,000 | $2.00 | $192.00K | 806,230 |
| Todd Wider Director | Sep 14, 2025 | Tax withholding | −21,892 | $8.77 | $191.99K | 784,338 |
| Paul Elliot Mann Chief Executive Officer, Director, 10% owner | Sep 9, 2025 | Tax withholding | −234,466 | $8.53 | $2.00M | 8,165,268 |
| Paul Elliot Mann Chief Executive Officer, Director, 10% owner | Sep 9, 2025 | Option exercise | +1,000,000 | $2.00 | $2.00M | 8,399,734 |
| Paul Elliot Mann Chief Executive Officer, Director, 10% owner | Sep 9, 2025 | Option exercise | +216,000 | $2.00 | $432.00K | 7,450,378 |
| Paul Elliot Mann Chief Executive Officer, Director, 10% owner | Sep 9, 2025 | Sale(10b5-1 plan) | −81,077 | $8.39 | $680.24K | 8,084,191 |
| Paul Elliot Mann Chief Executive Officer, Director, 10% owner | Sep 9, 2025 | Tax withholding | −50,644 | $8.53 | $431.99K | 7,399,734 |
| Robert Ainscow Chief Operating Officer | Sep 9, 2025 | Option exercise | +12,000 | $2.00 | $24.00K | 1,569,158 |
| Robert Ainscow Chief Operating Officer | Sep 9, 2025 | Option exercise | +135,000 | $2.00 | $270.00K | 1,701,345 |
| Robert Ainscow Chief Operating Officer | Sep 9, 2025 | Tax withholding | −2,813 | $8.53 | $23.99K | 1,566,345 |
| Robert Ainscow Chief Operating Officer | Sep 9, 2025 | Tax withholding | −31,652 | $8.53 | $269.99K | 1,669,693 |
| Robert Ainscow Chief Operating Officer | Sep 9, 2025 | Tax withholding | −4,396 | $8.53 | $37.50K | 1,557,158 |
| Robert Ainscow Chief Operating Officer | Sep 9, 2025 | Option exercise | +150,000 | $0.25 | $37.50K | 1,564,554 |
| Paul Elliot Mann Chief Executive Officer, Director, 10% owner | Sep 8, 2025 | Sale(10b5-1 plan) | −81,076 | $8.53 | $691.58K | 7,234,378 |
| Robert Ainscow Chief Operating Officer | Sep 8, 2025 | Sale(10b5-1 plan) | −8,438 | $8.53 | $71.98K | 1,411,554 |
| Ralph L. Hunter JR Director | Sep 6, 2025 | Award | +10,470 | – | – | 10,470 |
| Duncan Moore Director | Aug 29, 2025 | Sale | −75,000 | $9.28 | $696.00K | 994,553 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| Kiessling Heather Affiliate | Oct 16, 2026 | 21,830 | $47.98K | Oct 16, 2026 | Acquired as compensation - Restricted Stock Award |
| Robert Ainscow OFFICER | Oct 14, 2026 | 22,500 | $46.58K | Oct 14, 2026 | Acquired as compensation --Restricted Stock Award |
| Wider Todd Director | Sep 25, 2026 | 200,000 | $590.00K | Sep 25, 2026 | Compensation |
| George Ainscow Donald Affiliate | Sep 2, 2026 | 50,000 | $194.39K | Sep 2, 2026 | Acquired as compensation - Restricted Stock Award |
| Robert Ainscow OFFICER | Sep 2, 2026 | 33,438 | $126.40K | Sep 2, 2026 | Acquired as compensation --Restricted Stock Award |
| Paul Elliot Mann DIRECTOR, OFFICER | Sep 2, 2026 | 251,275 | $949.82K | Sep 2, 2026 | Acquired as compensation --Restricted Stock Award |
| Donald George Ainscow OFFICER | Jun 30, 2026 | 100,000 | $622.00K | Jun 30, 2026 | Private placement |
| Wider Todd Director | Jun 29, 2026 | 100,000 | $628.00K | Jun 29, 2026 | Compensation |
| Michael Gorley DIRECTOR | Jun 29, 2026 | 30,000 | $186.60K | Jun 29, 2026 | Acquired as compensation -- Restricted Stock Award |
| Robert Ainscow OFFICER | Jun 8, 2026 | 8,438 | $58.14K | Jun 8, 2026 | ACQUIRED AS COMPENSATION -- RESTRICTED STOCK AWARD |
| Paul Elliot Mann DIRECTOR, OFFICER | Jun 1, 2026 | 251,275 | $1.95M | Jun 1, 2026 | Acquired as compensation --Restricted Stock Award |
| Duncan Moore DIRECTOR | Apr 17, 2026 | 11,642 | $62.63K | Apr 16, 2026 | Acquired as compensation --Restricted Stock Award |
| Robert Ainscow OFFICER | Apr 16, 2026 | 22,500 | $121.05K | Apr 16, 2026 | Acquired as compensation --Restricted Stock Award |
| Kiessling Heather Officer | Apr 15, 2026 | 46,248 | $231.24K | Apr 15, 2026 | Restricted Stock Award |
| Robert Ainscow OFFICER | Apr 13, 2026 | 25,000 | $112.00K | Apr 13, 2026 | Acquired as compensation --Restricted Stock Award |