ASPI

ASP Isotopes Inc. Common Stock$4.03+0.48 (+13.70%)

Prev Close$3.54·MCap$335.7M·P/E—·Vol3.57M·Yield—

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Buys (12M)

$0.00

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Sells (12M)

$14.88M

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Net Activity

Net Seller

$14.88M

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Active Insiders

last 12 mo

Over the past 12 months, insider activity at ASP Isotopes Inc. Common Stock (ASPI) has been exclusively selling, with 0 insider purchases totaling $0.00 and 24 insider sales totaling $14.88M. The most recent insider transaction was by Kiessling Heather (officer: Chief Financial Officer), who sold $145.2K worth of shares on Jul 2, 2026. ASP Isotopes Inc. Common Stock operates in the Basic Materials sector, within the Chemicals industry, with a market cap of $335.7M.

ASPI Insider Trading Activity

Date	Insider	Role	Type	Shares	Avg Price	Value	Shares After
Jul 2, 2026	Kiessling Heather	officer: Chief Financial Officer	Sell	23,124	$6.28	$145.2K	1,526,252
Jul 2, 2026	Ainscow Donald George	officer: EVP, Gen Counsel, Secretary	Sell	100,000	$6.14	$614.0K	800,000
Jul 1, 2026	Gorley Michael	director	Sell	30,000	$6.27	$188.1K	87,908-25%
Jul 1, 2026	Wider Todd	director	Sell	100,000	$6.19	$618.5K	722,247
Jun 10, 2026	Ainscow Robert	officer: COO	Sell	8,438	$7.00	$59.1K	2,281,879
Jun 3, 2026	Mann Paul Elliot	director, officer: Chairman and CEO	Sell	251,275	$7.98	$2.00M	9,747,182
Apr 17, 2026	Moore Duncan	director	Sell	11,642	$5.20	$60.6K	1,044,928
Apr 17, 2026	Ainscow Robert	officer: COO	Sell	22,500	$5.21	$117.1K	1,490,317
Apr 17, 2026	Kiessling Heather	officer: Chief Financial Officer	Sell	23,124	$5.48	$126.7K	709,376
Apr 13, 2026	Ainscow Robert	officer: COO	Sell	25,000	$4.51	$112.8K	1,512,817
Mar 6, 2026	Ainscow Robert	officer: COO	Sell	8,438	$5.44	$45.9K	1,537,817
Mar 2, 2026	Mann Paul Elliot	officer: Executive Chairman	Sell	162,153	$5.44	$881.5K	7,597,385
Dec 18, 2025	Kiessling Heather	Chief Financial Officer	Sell	80,000	$5.80	$463.8K	0
Dec 8, 2025	Ainscow Robert	Interim CEO and COO	Sell	8,438	$6.20	$52.3K	0
Dec 1, 2025	Mann Paul Elliot	Executive Chairman	Sell	162,153	$5.75	$932.9K	0
Nov 25, 2025	Ainscow Robert	Interim CEO and COO	Sell	25,000	$5.77	$144.2K	0
Nov 17, 2025	Ainscow Robert	Interim CEO and COO	Sell	67,500	$7.51	$506.7K	0
Nov 17, 2025	Mann Paul Elliot	Executive Officer	Sell	162,500	$6.97	$1.13M	0
Oct 14, 2025	Ainscow Robert	Interim CEO and COO	Sell	22,500	$13.60	$306.0K	0
Sep 30, 2025	Gorley Michael	Director	Sell	64,000	$9.75	$624.2K	0
Sep 14, 2025	Wider Todd	Director	Sell	96,000	$8.76	$840.8K	0
Sep 8, 2025	Ainscow Robert	Chief Operating Officer	Sell	47,299	$8.53	$403.4K	0
Sep 8, 2025	Mann Paul Elliot	Chief Executive Officer	Sell	447,263	$8.50	$3.80M	0
Aug 29, 2025	Moore Duncan	Director	Sell	75,000	$9.28	$696.2K	0
Apr 15, 2025	Ainscow Robert	Chief Operating Officer	Sell	200,000	$5.61	$1.12M	0
Apr 15, 2025	Mann Paul Elliot	Chief Executive Officer	Sell	950,000	$5.61	$5.33M1.0% OS	0
Apr 29, 2024	Ryan Robert John Andrew	Director	Buy	20,547	$3.38	$69.5K	0
Apr 26, 2024	Ryan Robert John Andrew	Director	Buy	5,000	$3.48	$17.4K	0
Apr 25, 2024	Ryan Robert John Andrew	Director	Buy	9,500	$3.42	$32.5K	0
Jan 14, 2024	Ryan Robert John Andrew	Director	Buy	18,346	$2.29	$42.0K	0
Oct 26, 2023	Wider Todd	Director	Buy	94,844	$0.96	$91.1K	0
Aug 10, 2023	Moore Duncan	Director	Buy	104,167	$0.96	$100.0K	0
Jun 29, 2023	Moore Duncan	Director	Buy	50,000	$0.50	$25.0K	0
May 18, 2023	Moore Duncan	Director	Buy	20,000	$0.31	$6.2K	0
May 10, 2023	Moore Duncan	Director	Buy	10,000	$0.50	$5.0K	0
Apr 6, 2023	Moore Duncan	Director	Buy	20,000	$1.00	$20.0K	0

ASPI Insider Buying Activity

The following table shows recent insider purchases of ASP Isotopes Inc. Common Stock (ASPI) stock reported via SEC Form 4 filings.

Date	Insider	Role	Type	Shares	Avg Price	Value
Apr 29, 2024	Ryan Robert John Andrew	Director	Buy	20,547	$3.38	$69.5K
Apr 26, 2024	Ryan Robert John Andrew	Director	Buy	5,000	$3.48	$17.4K
Apr 25, 2024	Ryan Robert John Andrew	Director	Buy	9,500	$3.42	$32.5K
Jan 14, 2024	Ryan Robert John Andrew	Director	Buy	18,346	$2.29	$42.0K
Oct 26, 2023	Wider Todd	Director	Buy	94,844	$0.96	$91.1K
Aug 10, 2023	Moore Duncan	Director	Buy	104,167	$0.96	$100.0K
Jun 29, 2023	Moore Duncan	Director	Buy	50,000	$0.50	$25.0K
May 18, 2023	Moore Duncan	Director	Buy	20,000	$0.31	$6.2K
May 10, 2023	Moore Duncan	Director	Buy	10,000	$0.50	$5.0K
Apr 6, 2023	Moore Duncan	Director	Buy	20,000	$1.00	$20.0K

ASPI Insider Selling Activity

The following table shows recent insider sales of ASP Isotopes Inc. Common Stock (ASPI) stock reported via SEC Form 4 filings.

Date	Insider	Role	Type	Shares	Avg Price	Value	Shares After
Jul 2, 2026	Kiessling Heather	officer: Chief Financial Officer	Sell	23,124	$6.28	$145.2K	1,526,252
Jul 2, 2026	Ainscow Donald George	officer: EVP, Gen Counsel, Secretary	Sell	100,000	$6.14	$614.0K	800,000
Jul 1, 2026	Gorley Michael	director	Sell	30,000	$6.27	$188.1K	87,908-25%
Jul 1, 2026	Wider Todd	director	Sell	100,000	$6.19	$618.5K	722,247
Jun 10, 2026	Ainscow Robert	officer: COO	Sell	8,438	$7.00	$59.1K	2,281,879
Jun 3, 2026	Mann Paul Elliot	director, officer: Chairman and CEO	Sell	251,275	$7.98	$2.00M	9,747,182
Apr 17, 2026	Moore Duncan	director	Sell	11,642	$5.20	$60.6K	1,044,928
Apr 17, 2026	Ainscow Robert	officer: COO	Sell	22,500	$5.21	$117.1K	1,490,317
Apr 17, 2026	Kiessling Heather	officer: Chief Financial Officer	Sell	23,124	$5.48	$126.7K	709,376
Apr 13, 2026	Ainscow Robert	officer: COO	Sell	25,000	$4.51	$112.8K	1,512,817
Mar 6, 2026	Ainscow Robert	officer: COO	Sell	8,438	$5.44	$45.9K	1,537,817
Mar 2, 2026	Mann Paul Elliot	officer: Executive Chairman	Sell	162,153	$5.44	$881.5K	7,597,385
Dec 18, 2025	Kiessling Heather	Chief Financial Officer	Sell	80,000	$5.80	$463.8K	0
Dec 8, 2025	Ainscow Robert	Interim CEO and COO	Sell	8,438	$6.20	$52.3K	0
Dec 1, 2025	Mann Paul Elliot	Executive Chairman	Sell	162,153	$5.75	$932.9K	0
Nov 25, 2025	Ainscow Robert	Interim CEO and COO	Sell	25,000	$5.77	$144.2K	0
Nov 17, 2025	Ainscow Robert	Interim CEO and COO	Sell	67,500	$7.51	$506.7K	0
Nov 17, 2025	Mann Paul Elliot	Executive Officer	Sell	162,500	$6.97	$1.13M	0
Oct 14, 2025	Ainscow Robert	Interim CEO and COO	Sell	22,500	$13.60	$306.0K	0
Sep 30, 2025	Gorley Michael	Director	Sell	64,000	$9.75	$624.2K	0
Sep 14, 2025	Wider Todd	Director	Sell	96,000	$8.76	$840.8K	0
Sep 8, 2025	Ainscow Robert	Chief Operating Officer	Sell	47,299	$8.53	$403.4K	0
Sep 8, 2025	Mann Paul Elliot	Chief Executive Officer	Sell	447,263	$8.50	$3.80M	0
Aug 29, 2025	Moore Duncan	Director	Sell	75,000	$9.28	$696.2K	0
Apr 15, 2025	Ainscow Robert	Chief Operating Officer	Sell	200,000	$5.61	$1.12M	0
Apr 15, 2025	Mann Paul Elliot	Chief Executive Officer	Sell	950,000	$5.61	$5.33M1.0% OS	0