ASP Isotopes
Develops isotope-enrichment technology across specialist isotopes, nuclear fuels, radiopharmacy, and helium.
$3.92
After-hours close+0.04 (+1.04%)
At close$3.88(−3.96%)
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Breakdown13F · Form 4
Institutions 53.21%66.99M sharesInsiders 11.81%14.87M sharesOther 34.98%44.04M shares
Shares outstanding 125.90M · Float 108.99M · 86.6% free float
A Form 4 total here can count shares the filer formally disclaims — an award voted by proxy, for instance — which the holder's own Schedule 13D/G excludes, so where the two disagree the schedule's smaller figure is used.
Institutions13F, as of Jun 30, 2026
202 holders · 66.99M shares · 41 new positions · 118 increased · 51 reduced · 30 closed
| Holder | Shares | % outstanding | Chg q/q | Filed |
|---|---|---|---|---|
| BlackRock, Inc. | 9.22M | 7.32% | +889.1K | Aug 7, 2026 |
| Encompass Capital Advisors LLC | 6.56M | 5.21% | −350.3K | Aug 14, 2026 |
| Vanguard Capital Management LLC | 4.98M | 3.96% | −77.5K | Aug 13, 2026 |
| Rovida Investment Management Ltd | 4.10M | 3.26% | 0 | Aug 5, 2026 |
| UBS Group AG | 3.25M | 2.58% | +405.9K | Aug 13, 2026 |
| Geode Capital Management, LLC | 2.95M | 2.34% | +205.4K | Aug 12, 2026 |
| Alyeska Investment Group, L.P. | 2.84M | 2.26% | +151.3K | Aug 14, 2026 |
| State Street Corp | 2.60M | 2.06% | +273.4K | Aug 7, 2026 |
Beneficial owners13D/G · 5% or more, as filed
| Holder | % of class | Shares | Form | Filed |
|---|---|---|---|---|
| Mann Paul Elliot | 7.00% | 7.76M | 13G | Feb 17, 2026 ↗ |
| AWM Investment Company, Inc. | 6.90% | 13G | Aug 14, 2025 ↗ | |
| BlackRock, Inc. | 6.60% | 8.27M | 13G | Apr 27, 2026 ↗ |
| AK Jensen Investment Management Limited | 6.60% | 4.71M | 13G | Feb 12, 2025 ↗ |
| AK Jensen Investment Management Ltd | 5.40% | 4.96M | 13G | Nov 14, 2025 ↗ |
| Encompass Capital Advisors LLC | 5.13% | 6.41M | 13G | Jan 23, 2026 ↗ |
InsidersForm 4
| Insider | Role | Shares | % outstanding | Filed |
|---|---|---|---|---|
| Paul Elliot Mann | director, officer: Chairman and CEO | 7.76M | 6.16% | Jun 3, 2026 |
| Robert Ainscow | officer: COO | 2.28M | 1.81% | Jun 10, 2026 |
| Heather Kiessling | officer: Chief Financial Officer | 1.53M | 1.21% | Jul 2, 2026 |
| Duncan Moore | director | 1.04M | 0.83% | Apr 17, 2026 |
| Donald George Ainscow | officer: EVP, Gen Counsel, Secretary | 800.0K | 0.64% | Jul 2, 2026 |
| Todd Wider | director | 672.2K | 0.53% | Jul 1, 2026 |
| Robert John Andrew Ryan | director | 652.2K | 0.52% | Dec 22, 2025 |
| Michael Gorley | director | 87.9K | 0.07% | Jul 1, 2026 |
| Ralph L. JR Hunter | director | 47.0K | 0.04% | Dec 22, 2025 |
1 ten-percent owner holds 6.75M shares by Form 4, outside the officers-and-directors figure above · 4 people have not refiled in the last 18 months (12.34M shares), so they are not in the figure above
Latest trades
| Date | Insider | Type | Shares | Avg price | Owned after |
|---|---|---|---|---|---|
| Jun 30, 2026 | Donald George Ainscowofficer: EVP, Gen Counsel, Secretary | Sale | 100,000 | $6.14 | 800,000 |
| Jul 1, 2026 | Heather Kiesslingofficer: Chief Financial Officer | Sale | 23,124 | $6.28 | 1,526,252 |
| Jun 30, 2026 | Michael Gorleydirector | Sale | 30,000 | $6.27 | 87,908 |
| Jun 30, 2026 | Todd Widerdirector | Sale | 50,000 | $6.12 | 672,247 |
| Jun 29, 2026 | Todd Widerdirector | Sale | 50,000 | $6.25 | 722,247 |
| Jun 8, 2026 | Robert Ainscowofficer: COO | Sale | 8,438 | $7.00 | 2,281,879 |
| Jun 3, 2026 | Paul Elliot Manndirector, officer: Chairman and CEO | Sale | 83,759 | $7.76 | 9,579,845 |
| Jun 2, 2026 | Paul Elliot Manndirector, officer: Chairman and CEO | Sale | 83,758 | $8.29 | 9,663,424 |
| Jun 1, 2026 | Paul Elliot Manndirector, officer: Chairman and CEO | Sale | 83,758 | $7.88 | 9,747,182 |
| Apr 16, 2026 | Duncan Mooredirector | Sale | 11,642 | $5.21 | 1,044,928 |
CongressHouse and Senate disclosures
Not reported.