Comparable stake leader
Paul Elliot Mann
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001921865.
Comparable stake leader
Paul Elliot Mann
Disclosed value leader
Paul Elliot Mann
Comparable rows
50/50
Latest evidence
01 Jul 2026
Ownership snapshot
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Quick read
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| Paul Elliot Mann |
3/4/5
13D/G
Chairman and CEO, Director · Mann Paul Elliot
|
7%
from 13D/G
|
$74,339,597
9,579,845 shares
|
-$4,560,257 | 28 May 2026 |
| BlackRock, Inc. |
13F
13D/G
Company
|
6.6%
from 13D/G
|
$57,330,971
9,217,198 shares
|
— | 30 Jun 2026 |
| AK Jensen Investment Management Ltd |
13D/G
3/4/5
10%+ Owner
|
5.4%
|
$47,669,611
4,955,261 shares
|
+$2,373,350 | 30 Sep 2025 |
| Encompass Capital Advisors LLC |
13F
13D/G
Company
|
5.1%
from 13D/G
|
$40,814,110
6,561,754 shares
|
— | 30 Jun 2026 |
| BNP Paribas Asset Management UK Ltd |
13D/G
|
0.9%
|
$7,073,002
944,326 shares
|
-$20,102,329 | 31 Dec 2025 |
| Robert Ainscow |
3/4/5
COO
|
1.8%
|
$15,970,871
2,281,879 shares
|
-$1,416,050 | 08 Jun 2026 |
| Heather Kiessling |
3/4/5
Chief Financial Officer
|
1.2%
|
$9,584,862
1,526,252 shares
|
-$735,732 | 01 Jul 2026 |
| Duncan Moore |
3/4/5
Director
|
0.83%
|
$5,438,850
1,044,928 shares
|
-$756,829 | 12 Nov 2025 |
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Net insider flow leans to selling over the last 12 months. Net value: -$10,162,528.
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 512,837 | $0 | $3,629,213 | -$3,629,213 |
| 3-6 | 162,153 | 90,704 | $881,464 | $463,052 | +$418,412 |
| 6-9 | 0 | 325,591 | $0 | $1,881,722 | -$1,881,722 |
| 9-12 | 0 | 586,199 | $0 | $5,070,005 | -$5,070,005 |
Reporting owners
Showing 1-14 of 14 reporting-owner rows connected to ASP Isotopes Inc.. Open a relationship link for the CIK-to-CIK filing trail.
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Paul Elliot Mann | Chairman and CEO, Director | $74,339,597 | -$4,560,257 | -5.8% | Filing P/S | 28 May 2026 |
| AK Jensen Investment Management Ltd | 10%+ Owner | $40,490,134 | Mixed | 11 Oct 2024 | ||
| Robert Ainscow | Coo | $15,970,871 | -$1,416,050 | -8.1% | Filing P/S | 08 Jun 2026 |
| Heather Kiessling | Chief Financial Officer | $9,584,862 | -$735,732 | -7.1% | Filing P/S | 01 Jul 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 | $4,912,000 | -$614,000 | -11% | Filing P/S | 30 Jun 2026 |
| Todd Wider | Director | $4,114,151 | -$1,267,323 | -24% | Filing P/S | 29 Jun 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 | $551,183 | -$812,337 | -60% | Filing P/S | 30 Jun 2026 |
| Ralph L. Hunter Jr. | Director | $278,346 | Mixed | 18 Dec 2025 |
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Heather Kiessling | ASPI | Common Stock | Sale | -1.49% | $145,219 | $6.28 | -23,124 | 1,526,252 | 01 Jul 2026 | Direct |
| Donald George Ainscow | ASPI | Common Stock | Sale | -11.1% | $614,000 | $6.14 | -100,000 | 800,000 | 30 Jun 2026 | Direct |
| Todd Wider | ASPI | Common Stock | Sale | -6.92% | $306,000 | $6.12 | -50,000 | 672,247 | 30 Jun 2026 | Direct |
| Michael Gorley | ASPI | Common Stock | Sale | -25.4% | $188,100 | $6.27 | -30,000 | 87,908 | 30 Jun 2026 | Direct |
| Todd Wider | ASPI | Common Stock | Sale | -6.47% | $312,500 | $6.25 | -50,000 | 722,247 | 29 Jun 2026 | Direct |
| Robert Ainscow | ASPI | Common Stock | Sale | -0.37% | $59,058 | $7.00 | -8,438 | 2,281,879 | 08 Jun 2026 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Sale | -0.87% | $649,970 | $7.76 | -83,759 | 9,579,845 | 03 Jun 2026 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Sale | -0.86% | $694,354 | $8.29 | -83,758 | 9,663,424 | 02 Jun 2026 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Sale | -0.85% | $660,013 | $7.88 | -83,758 | 9,747,182 | 01 Jun 2026 | Direct |
| Paul Elliot Mann | ASPI | Common Stock | Award | 29.4% | 2,233,555 | 9,830,940 | 28 May 2026 | Direct | ||
| Robert Ainscow | ASPI | Common Stock | Award | 53.7% | 800,000 | 2,290,317 | 28 May 2026 | Direct | ||
| Donald George Ainscow | ASPI | Common Stock | Award | 80% | 400,000 | 900,000 | 28 May 2026 | Direct | ||
| Heather Kiessling | ASPI | Common Stock | Award | 118.4% | 840,000 | 1,549,376 | 28 May 2026 | Direct | ||
| 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 |