ASP Isotopes Inc. Common Stock
ASP Isotopes Inc. Common Stock (ASPI) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · ASPI · as of Sep 30, 2025
Ownership Breakdown
173
Institutional Holders
▲ 27 vs Q2
$508.85M
Total Inst. Value
▲ $187.20M vs Q2
83.10M
Shares Outstanding
freeFloat 80.77%
52.91M
13F Shares Held
▲ 9.20M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
ASPI largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
BLACKROCK, INC. miscellaneous chemical products | 5.46M | 7.48% | 7.48% | $52.53B | Nov 12, 2025 | ▲ 1.43M |
VANGUARD GROUP INC miscellaneous chemical products | 4.52M | 6.19% | 6.19% | $43.45B | Nov 7, 2025 | ▲ 1.24M |
ROVIDA INVESTMENT MANAGEMENT LTD miscellaneous chemical products | 3.20M | 4.38% | 4.38% | $30.69B | Nov 12, 2025 | ▲ 1.00M |
AWM INVESTMENT COMPANY, INC. miscellaneous chemical products | 2.96M | 4.05% | 4.05% | $28.46B | Nov 13, 2025 | ▼ 972.6K |
ALYESKA INVESTMENT GROUP, L.P. miscellaneous chemical products | 2.82M | 3.87% | 3.87% | $27.15B | Nov 17, 2025 | ▼ 1.36M |
CAPITAL RESEARCH GLOBAL INVESTORS miscellaneous chemical products | 2.04M | 2.80% | 2.80% | $19.66B | Nov 13, 2025 | ▼ 824.5K |
GEODE CAPITAL MANAGEMENT, LLC miscellaneous chemical products | 1.86M | 2.55% | 2.55% | $17.92B | Nov 12, 2025 | ▲ 514.4K |
SUSQUEHANNA INTERNATIONAL GROUP, LLP miscellaneous chemical products | 1.79M | 2.46% | 2.46% | $17.26B | Nov 14, 2025 | ▲ 567.2K |
SUSQUEHANNA INTERNATIONAL GROUP, LLP miscellaneous chemical products | 1.77M | 2.42% | 2.42% | $17.02B | Nov 14, 2025 | ▲ 337.0K |
PHILADELPHIA FINANCIAL MANAGEMENT OF SAN FRANCISCO, LLC miscellaneous chemical products | 1.66M | 2.28% | 2.28% | $15.98B | Nov 14, 2025 | ▼ 1.01M |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
32
Increased
+15.72M shares5
New Positions
first time holders13
Decreased
−6.32M shares0
Sold Out
fully exitedNet shares change (top 50)
+9.40M
+15.72M / −6.32M
Net new holders
+24
5 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
ASPI insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
4
Buy transactions
6
Sell transactions
0.67
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Mann Paul Elliot Chairman and CEO | May 28, 2026 | Award | 2,233,555 | — | — | 9.83M | Form 4 ↗ |
Mann Paul Elliot Chairman and CEO | Jun 1, 2026 | Sale | 83,758 | $7.88 | $660.0K | 9.75M | Form 4 ↗ |
Mann Paul Elliot Chairman and CEO | Jun 2, 2026 | Sale | 83,758 | $8.29 | $694.4K | 9.66M | Form 4 ↗ |
Mann Paul Elliot Chairman and CEO | Jun 3, 2026 | Sale | 83,759 | $7.76 | $650.0K | 9.58M | Form 4 ↗ |
Ainscow Robert Chief Operating Officer | May 28, 2026 | Award | 800,000 | — | — | 2.29M | Form 4 ↗ |
Ainscow Donald George EVP, Gen Counsel, Secretary | May 28, 2026 | Award | 400,000 | — | — | 900.0K | Form 4 ↗ |
Kiessling Heather Chief Financial Officer | May 28, 2026 | Award | 840,000 | — | — | 1.55M | Form 4 ↗ |
Ainscow Robert COO | Apr 16, 2026 | Sale | 22,500 | $5.21 | $117.1K | 1.49M | Form 4 ↗ |
Kiessling Heather Chief Financial Officer | Apr 15, 2026 | Sale | 23,124 | $5.48 | $126.7K | 709.4K | Form 4 ↗ |
Moore Duncan director | Dec 18, 2025 | Award | 36,548 | — | — | 1.06M | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
ASP Isotopes Inc. Common Stock (ASPI) is primarily owned by institutional investors, who hold approximately 63.7% of total shares outstanding. Company insiders own approximately 19.23%, while retail and public investors account for the remaining 17.09%.
The largest institutional shareholder of ASP Isotopes Inc. Common Stock is BLACKROCK, INC., holding approximately 5.46 million shares — equal to 7.48% of outstanding shares — as of September 30, 2025.
A total of 173 institutional investors currently hold ASPI stock, with a combined institutional value of approximately $508,847,148 as of the most recent 13F filing period.
Frequently asked questions
ASPI ownershipASP Isotopes Inc. Common Stock (ASPI) is primarily owned by institutional investors, who hold approximately 63.7% of shares. The largest shareholder is BLACKROCK, INC. with a 7.48% stake. Company insiders hold 19.23%. Data sourced from SEC Form 13F as of September 30, 2025.