ASP Isotopes Inc.
Ownership
Ownership Structure
Who owns ASP Isotopes Inc. (ASPI)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 86.8% of the shares are freely tradable; institutional investors hold 57.1%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 6.01 | 9,217,198 | +10.7 | 06/30/2026 |
| Encompass Capital Advisors LLC | 4.28 | 6,561,754 | -5.1 | 06/30/2026 |
| Vanguard Capital Management, LLC | 3.25 | 4,982,953 | -1.5 | 06/30/2026 |
| Rovida Investment Management Ltd | 2.67 | 4,100,000 | +0.0 | 06/30/2026 |
| UBS Group AG | 2.12 | 3,247,633 | +14.3 | 06/30/2026 |
| Geode Capital Management, LLC | 1.92 | 2,945,901 | +7.5 | 06/30/2026 |
| Alyeska Investment Group, L.P. | 1.85 | 2,843,503 | +5.6 | 06/30/2026 |
| State Street Corp | 1.69 | 2,595,573 | +11.8 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.86 | 4,383,125 | +22.0 | 09/30/2026 |
| iShares Russell 2000 ETF | 2.37 | 3,627,115 | -1.1 | 09/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Mann Paul Elliot | Chairman and CEO | 9,328,570 | 18,657,140 $ | Sep 4, 2026 | direct |
| Ainscow Robert | COO | 2,225,941 | 4,451,882 $ | Oct 14, 2026 | direct |
| Kiessling Heather | Chief Financial Officer | 1,504,422 | 3,008,844 $ | Oct 16, 2026 | direct |
| Ainscow Donald George | EVP, Gen Counsel, Secretary | 776,322 | 1,552,644 $ | Sep 2, 2026 | direct |
| Ryan Robert John Andrew | Director | 675,222 | 1,350,444 $ | Sep 30, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Oct 16, 2026 | Kiessling Heather | Chief Financial Officer | Sell | 21,830 | 2.19 | 47,808 |
| Oct 14, 2026 | Ainscow Robert | COO | Sell | 22,500 | 2.11 | 47,565 |
| Sep 30, 2026 | Ryan Robert John Andrew | Director | Buy | 15,000 | 2.68 | 40,200 |
| Sep 28, 2026 | Ryan Robert John Andrew | Director | Buy | 8,000 | 2.70 | 21,600 |
| Sep 8, 2026 | Ainscow Robert | COO | Sell | 8,438 | 4.29 | 36,216 |
| Sep 4, 2026 | Mann Paul Elliot | Chairman and CEO | Sell | 83,759 | 4.10 | 343,412 |
| Sep 3, 2026 | Mann Paul Elliot | Chairman and CEO | Sell | 83,758 | 3.92 | 328,331 |
| Sep 2, 2026 | Ainscow Donald George | EVP, Gen Counsel, Secretary | Sell | 23,678 | 3.89 | 92,107 |
| Sep 2, 2026 | Ainscow Robert | COO | Sell | 25,000 | 3.91 | 97,625 |
| Sep 2, 2026 | Mann Paul Elliot | Chairman and CEO | Sell | 83,758 | 3.91 | 327,494 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: October 30, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.