Quick Takeaways
- ASPI - ASP Isotopes Inc. has 14 insiders with reported activity on this page.
- Net insider value flow over the last year: -$6,533,315.
- Recent transaction rows are available for direct filing-level review.
Insider Transactions Reported by 14 Insiders of ASP Isotopes Inc.
- Symbol
- ASPI on Nasdaq
- Location
- Dallas, TX
What Changed
- Buy value: $881,464; sell value: $7,414,778.
- Net share flow: -840,341.
Why This Matters
- This page gives a plain-language issuer insider context before you inspect transaction-level evidence.
- Use the filing links below to verify timestamps, codes, and ownership impacts directly from SEC forms.
Source Evidence
Filed on Form 4
See Original Filing
Issuer insider activity is sourced from SEC Forms 3, 4, and 5.
Insider trading overview
Last 12 monthsNet insider flow leans to selling over the last 12 months. Net value: -$6,533,315.
Buys
$881,464
Shares: 162,153
Insiders: 1
Sells
$7,414,779
Shares: 1,002,494
Insiders: 6
Net
-$6,533,315
Shares: -840,341
Insiders: -5
| Window (months) | Buy shares | Sell shares | Buy $ | Sell $ | Net $ |
|---|---|---|---|---|---|
| 0-3 | 162,153 | 90,704 | $881,464 | $463,052 | +$418,412 |
| 3-6 | 0 | 505,591 | $0 | $3,232,982 | -$3,232,982 |
| 6-9 | 0 | 406,199 | $0 | $3,718,745 | -$3,718,745 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
ASP Isotopes Inc. executives and other stock owners filed with the SEC include:
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Mann Paul Elliot | Executive Chairman | $41,299,384 | -$2,555,921 | -5.8% | Filing P/S | 02 Mar 2026 |
| AK Jensen Investment Management Ltd | 10%+ Owner | $40,490,134 | Mixed | 11 Oct 2024 | ||
| Robert Ainscow | Coo | $7,757,099 | -$1,356,993 | -15% | Filing P/S | 16 Apr 2026 |
| Hendrik Strydom | Director, 10%+ Owner | $7,099,052 | Mixed | 15 Nov 2022 | ||
| Duncan Moore | Director | $5,438,850 | -$756,829 | -12% | Filing P/S | 12 Nov 2025 |
| Donald George Ainscow | EVP, Gen Counsel, Secretary | $5,380,000 | Mixed | 01 Aug 2025 | ||
| Todd Wider | Director | $4,571,702 | -$648,823 | -12% | Mixed | 18 Dec 2025 |
| Heather Kiessling | Chief Financial Officer | $3,885,961 | -$590,513 | -13% | Filing P/S | 15 Apr 2026 |
| Robert John Andrew Ryan | Director | $3,861,154 | Mixed | 18 Dec 2025 | ||
| Sergey Vasnetsov | Director | $3,685,063 | Mixed | 01 Mar 2023 | ||
| Ph.D. Einar Ronander | Chief Scientific Adviser, 10%+ Owner | $3,453,527 | Mixed | 09 Nov 2022 | ||
| Joshua J. Donfeld | Director | $1,060,000 | Filing P/S | 26 Oct 2023 | ||
| Michael Gorley | Director | $698,015 | -$624,237 | -47% | Mixed | 18 Dec 2025 |
| Ralph L. Hunter Jr. | Director | $278,346 | Mixed | 18 Dec 2025 |
Top shareholders of ASP Isotopes Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.
Methodology: rows are grouped by holder and ranked by the holder's primary source value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
| Holder | Source | Role / Reporting | Ownership % | Shares | Holdings Value | 12M Net Δ | As of | Details |
|---|---|---|---|---|---|---|---|---|
| Mann Paul Elliot |
13D/G
3/4/5
|
Executive Chairman |
7%
|
7,759,538
|
$58,118,940 | +$348,704 | 31 Dec 2025 | |
| AK Jensen Investment Management Ltd |
13D/G
3/4/5
|
10%+ Owner |
5.4%
|
4,955,261
|
$47,669,611 | +$2,373,350 | 30 Sep 2025 | |
| BlackRock, Inc. |
13D/G
13F
|
Company |
6.6%
|
8,274,763
|
$36,574,452 | +$19,091,638 | 31 Mar 2026 | |
| Encompass Capital Advisors LLC |
13D/G
|
— |
5.1%
|
6,413,362
|
$34,311,487 | $0 | 16 Jan 2026 | |
| VANGUARD GROUP INC |
13F
|
Company |
5.1%
|
6,406,244
|
$34,273,406 | — | 31 Dec 2025 | |
| Alyeska Investment Group, L.P. |
13F
|
Company |
3.9%
|
4,895,546
|
$26,191,171 | — | 31 Dec 2025 | |
| Rovida Investment Management Ltd |
13F
|
Company |
3.3%
|
4,100,000
|
$21,894,000 | — | 31 Dec 2025 | |
| UBS Group AG |
13F
|
Company |
1.9%
|
2,406,457
|
$12,874,546 | — | 31 Dec 2025 | |
| GEODE CAPITAL MANAGEMENT, LLC |
13F
|
Company |
1.9%
|
2,384,066
|
$12,757,945 | — | 31 Dec 2025 | |
| AWM Investment Company, Inc. |
13F
|
Company |
1.7%
|
2,124,496
|
$11,366,054 | — | 31 Dec 2025 | |
| STATE STREET CORP |
13F
|
Company |
1.5%
|
1,844,405
|
$9,867,567 | — | 31 Dec 2025 | |
| CITADEL ADVISORS LLC |
13F
|
Company |
1.4%
|
1,725,553
|
$9,231,709 | — | 31 Dec 2025 | |
| GOLDMAN SACHS GROUP INC |
13F
|
Company |
1.4%
|
1,715,292
|
$9,176,813 | — | 31 Dec 2025 | |
| MORGAN STANLEY |
13F
|
Company |
1.4%
|
1,709,783
|
$9,147,339 | — | 31 Dec 2025 | |
| JANE STREET GROUP, LLC |
13F
|
Company |
1.3%
|
1,586,961
|
$8,490,241 | — | 31 Dec 2025 | |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP |
13F
|
Company |
1.2%
|
1,516,643
|
$8,114,040 | — | 31 Dec 2025 | |
| Robert Ainscow |
3/4/5
|
COO |
1.2%
|
1,490,317
|
$7,757,099 | -$1,356,993 | 16 Apr 2026 | |
| EXCHANGE TRADED CONCEPTS, LLC |
13F
|
Company |
1.1%
|
1,400,314
|
$7,491,680 | — | 31 Dec 2025 | |
| Hendrik Strydom |
3/4/5
|
Director, 10%+ Owner |
—
class O/S missing
|
7,394,846
|
$7,099,052 | — | 15 Nov 2022 | |
| BNP Paribas Asset Management UK Ltd |
13D/G
|
— |
0.9%
|
944,326
|
$7,073,002 | -$20,102,329 | 31 Dec 2025 | |
| Duncan Moore |
3/4/5
|
Director |
0.83%
|
1,044,928
|
$5,438,850 | -$756,829 | 12 Nov 2025 | |
| Donald George Ainscow |
3/4/5
|
EVP, Gen Counsel, Secretary |
0.4%
|
500,000
|
$5,380,000 | — | 01 Aug 2025 | |
| BNP Paribas Asset Management Holding S.A. |
13F
|
Company |
0.75%
|
944,326
|
$5,052,000 | — | 31 Dec 2025 | |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC |
13F
|
Company |
0.71%
|
885,739
|
$4,738,704 | — | 31 Dec 2025 | |
| Todd Wider |
3/4/5
|
Director |
0.62%
|
772,247
|
$4,571,702 | -$648,823 | 18 Dec 2025 | |
| Telemark Asset Management, LLC |
13F
|
Company |
0.66%
|
825,000
|
$4,413,750 | — | 31 Dec 2025 | |
| MARSHALL WACE, LLP |
13F
|
Company |
0.65%
|
818,129
|
$4,376,991 | — | 31 Dec 2025 | |
| NORTHERN TRUST CORP |
13F
|
Company |
0.59%
|
745,909
|
$3,990,614 | — | 31 Dec 2025 | |
| Diametric Capital, LP |
13F
|
Company |
0.59%
|
737,304
|
$3,944,576 | — | 31 Dec 2025 | |
| Heather Kiessling |
3/4/5
|
Chief Financial Officer |
0.57%
|
709,376
|
$3,885,961 | -$590,513 | 15 Apr 2026 | |
| Robert John Andrew Ryan |
3/4/5
|
Director |
0.52%
|
652,222
|
$3,861,154 | — | 18 Dec 2025 | |
| Sergey Vasnetsov |
3/4/5
|
Director |
—
class O/S missing
|
3,838,607
|
$3,685,063 | — | 01 Mar 2023 | |
| Ph.D. Einar Ronander |
3/4/5
|
Chief Scientific Adviser, 10%+ Owner |
—
class O/S missing
|
3,597,424
|
$3,453,527 | — | 09 Nov 2022 | |
| WIM INVESTMENT MANAGEMENT Ltd |
13F
|
Company |
0.48%
|
601,400
|
$3,217,490 | — | 31 Dec 2025 | |
| Shay Capital LLC |
13F
|
Company |
0.46%
|
579,000
|
$3,097,650 | — | 31 Dec 2025 | |
| BARCLAYS PLC |
13F
|
Company |
0.4%
|
506,788
|
$2,711,316 | — | 31 Dec 2025 | |
| HITE Hedge Asset Management LLC |
13F
|
Company |
0.36%
|
449,883
|
$2,406,874 | — | 31 Dec 2025 | |
| GROUP ONE TRADING LLC |
13F
|
Company |
0.35%
|
444,345
|
$2,377,246 | — | 31 Dec 2025 | |
| Schonfeld Strategic Advisors LLC |
13F
|
Company |
0.33%
|
414,875
|
$2,219,580 | — | 31 Dec 2025 | |
| Pacer Advisors, Inc. |
13F
|
Company |
0.32%
|
404,372
|
$2,163,390 | — | 31 Dec 2025 | |
| Rathbones Group PLC |
13F
|
Company |
0.32%
|
399,599
|
$2,137,854 | — | 31 Dec 2025 | |
| Quantbot Technologies LP |
13F
|
Company |
0.32%
|
396,599
|
$2,121,805 | — | 31 Dec 2025 | |
| Saba Capital Management, L.P. |
13F
|
Company |
0.28%
|
356,377
|
$1,906,617 | — | 31 Dec 2025 | |
| TWO SIGMA INVESTMENTS, LP |
13F
|
Company |
0.28%
|
356,237
|
$1,905,868 | — | 31 Dec 2025 | |
| GSA CAPITAL PARTNERS LLP |
13F
|
Company |
0.26%
|
329,488
|
$1,763,000 | — | 31 Dec 2025 | |
| Caprock Group, LLC |
13F
|
Company |
0.26%
|
322,314
|
$1,724,380 | — | 31 Dec 2025 | |
| IMC-Chicago, LLC |
13F
|
Company |
0.23%
|
294,502
|
$1,575,586 | — | 31 Dec 2025 | |
| Burkehill Global Management, LP |
13F
|
Company |
0.2%
|
250,000
|
$1,337,500 | — | 31 Dec 2025 | |
| Bank of New York Mellon Corp |
13F
|
Company |
0.19%
|
243,987
|
$1,305,333 | — | 31 Dec 2025 | |
| BANK OF AMERICA CORP /DE/ |
13F
|
Company |
0.18%
|
230,856
|
$1,235,080 | — | 31 Dec 2025 |
Recent Insider Transactions by Companies or Individuals for ASP Isotopes Inc.
Showing up to 300 most recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | Value $ | * Price $ | Shares | Shares Owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Robert Ainscow | ASPI | Common Stock | Sale | -1.49% | $117,112 | $5.20 | -22,500 | 1,490,317 | 16 Apr 2026 | Direct |
| Duncan Moore | ASPI | Common Stock | Sale | -1.1% | $60,597 | $5.20 | -11,642 | 1,044,928 | 16 Apr 2026 | Direct |
| Heather Kiessling | ASPI | Common Stock | Sale | -3.16% | $126,673 | $5.48 | -23,124 | 709,376 | 15 Apr 2026 | Direct |
| Robert Ainscow | ASPI | Common Stock | Sale | -1.63% | $112,775 | $4.51 | -25,000 | 1,512,817 | 06 Mar 2026 | Direct |
| Robert Ainscow | ASPI | Common Stock | Sale | -0.55% | $45,894 | $5.44 | -8,438 | 1,537,817 | 06 Mar 2026 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Sale | 2.18% | $881,464 | $5.44 | 162,153 | 7,597,385 | 02 Mar 2026 | Direct |
| Duncan Moore | ASPI | Common Stock | Award | 3.58% | 36,548 | 1,056,570 | 18 Dec 2025 | Direct | ||
| Heather Kiessling | ASPI | Common Stock | Sale | -9.85% | $463,840 | $5.80 | -80,000 | 732,500 | 18 Dec 2025 | Direct |
| Todd Wider | ASPI | Common Stock | Award | 4.97% | 36,548 | 772,247 | 18 Dec 2025 | Direct | ||
| Robert John Andrew Ryan | ASPI | Common Stock | Award | 5.94% | 36,548 | 652,222 | 18 Dec 2025 | Direct | ||
| Ralph L. Hunter Jr. | ASPI | Common Stock | Award | 349.1% | 36,548 | 47,018 | 18 Dec 2025 | Direct | ||
| Michael Gorley | ASPI | Common Stock | Award | 44.9% | 36,548 | 117,908 | 18 Dec 2025 | Direct | ||
| Robert Ainscow | ASPI | Common Stock | Sale | -0.54% | $52,341 | $6.20 | -8,438 | 1,546,255 | 08 Dec 2025 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Sale | -2.05% | $932,866 | $5.75 | -162,153 | 7,759,538 | 01 Dec 2025 | Direct |
| Robert Ainscow | ASPI | Common Stock | Sale | -1.58% | $144,225 | $5.77 | -25,000 | 1,554,693 | 25 Nov 2025 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Sale | -0.63% | $288,450 | $5.77 | -50,000 | 7,921,691 | 25 Nov 2025 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Sale | -1.39% | $844,538 | $7.51 | -112,500 | 7,971,691 | 17 Nov 2025 | Direct |
| Robert Ainscow | ASPI | Common Stock | Sale | -4.1% | $506,722 | $7.51 | -67,500 | 1,579,693 | 17 Nov 2025 | Direct |
| Duncan Moore | ASPI | Common Stock | Award | 2.56% | 25,469 | 1,020,022 | 12 Nov 2025 | Direct | ||
| Todd Wider | ASPI | Common Stock | Award | 3.59% | 25,469 | 735,699 | 12 Nov 2025 | Direct | ||
| Robert Ainscow | ASPI | Common Stock | Sale | -1.35% | $305,978 | $13.60 | -22,500 | 1,647,193 | 14 Oct 2025 | Direct |
| Michael Gorley | ASPI | Common Stock | Sale | -44% | $624,237 | $9.75 | -64,000 | 81,360 | 30 Sep 2025 | Direct |
| Todd Wider | ASPI | Common Stock | Sale | -9.45% | $648,823 | $8.76 | -74,108 | 710,230 | 15 Sep 2025 | Direct |
| Todd Wider | ASPI | Common Stock | Tax liability | -2.72% | -21,892 | 784,338 | 14 Sep 2025 | Direct | ||
| Todd Wider | ASPI | Common Stock | Options Exercise | 13.5% | 96,000 | 806,230 | 14 Sep 2025 | Direct | ||
| Todd Wider | ASPI | Stock Option (right to buy) | Options Exercise | -100% | -96,000 | 0 | 14 Sep 2025 | Direct | ||
| Robert Ainscow | ASPI | Common Stock | Tax liability | -2.43% | -38,861 | 1,557,158 | 09 Sep 2025 | Direct | ||
| Robert Ainscow | ASPI | Common Stock | Options Exercise | 21.2% | 297,000 | 1,701,345 | 09 Sep 2025 | Direct | ||
| Robert Ainscow | ASPI | Employee Stock Option (right to buy) | Options Exercise | -100% | -297,000 | 0 | 09 Sep 2025 | Direct | ||
| Paul Elliot Mann | ASPI | Common Stock | Sale | -0.99% | $680,123 | $8.39 | -81,077 | 8,084,191 | 09 Sep 2025 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Tax liability | -3.71% | -285,110 | 7,399,734 | 09 Sep 2025 | Direct | ||
| Paul Elliot Mann | ASPI | Common Stock | Options Exercise | 16.9% | 1,216,000 | 8,399,734 | 09 Sep 2025 | Direct | ||
| Paul Elliot Mann | ASPI | Employee Stock Option (right to buy) | Options Exercise | -100% | -1,216,000 | 0 | 09 Sep 2025 | Direct | ||
| Robert Ainscow | ASPI | Common Stock | Sale | -0.59% | $71,945 | $8.53 | -8,438 | 1,411,554 | 08 Sep 2025 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Sale | -1.11% | $691,408 | $8.53 | -81,076 | 7,234,378 | 08 Sep 2025 | Direct |
| Ralph L. Hunter Jr. | ASPI | Common Stock | Award | 10,470 | 10,470 | 06 Sep 2025 | Direct | |||
| Duncan Moore | ASPI | Common Stock | Sale | -7.01% | $696,232 | $9.28 | -75,000 | 994,553 | 29 Aug 2025 | Direct |
| Donald George Ainscow | ASPI | Common Stock | Award | 400% | 400,000 | 500,000 | 01 Aug 2025 | Direct |
* An asterisk sign (*) next to the price indicates that the price is likely invalid.