ASP Isotopes

ASPI · NASDAQ

$2.03−$0.025 (−1.22%)TodayMarket closed · Oct 20, 7:46 PM ET

Prev close $2.05

Who owns ASPI

Largest institutional holders, from their latest 13F filings

The 10 largest institutions hold 33.6% of ASPI’s shares.

Mann (Paul Elliot)6.4%
BlackRock Institutional Trust Company, N.A.5.6%
Encompass Capital Advisors, LLC4.4%
Vanguard Capital Management, LLC3.3%
Next 6 largest institutions13.8%
All other shareholders66.4%

Top institutional holders of ASPI
Holder	Shares	% of shares	Change, last filing	Filed
Mann (Paul Elliot)	9.58M	6.43%	−251.28K	Jun 3, 2026
BlackRock Institutional Trust Company, N.A.	8.30M	5.57%	+706.85K	Jun 30, 2026
Encompass Capital Advisors, LLC	6.56M	4.40%	−350.30K	Jun 30, 2026
Vanguard Capital Management, LLC	4.98M	3.34%	−77.51K	Jun 30, 2026
AK Jensen Investment Management Ltd	4.96M	3.32%	+246.71K	Sep 30, 2025
Rovida Investment Management Ltd	4.10M	2.75%	+0	Jun 30, 2026
UBS Financial Services, Inc.	3.15M	2.11%	+409.16K	Jun 30, 2026
Geode Capital Management, L.L.C.	2.95M	1.98%	+205.44K	Jun 30, 2026
Alyeska Investment Group, L.P.	2.84M	1.91%	+151.34K	Jun 30, 2026
State Street Investment Management (US)	2.60M	1.74%	+273.41K	Jun 30, 2026

Largest mutual fund holders

Top mutual fund holders of ASPI
Holder	Shares	% of shares	Change, last filing	Filed
Vanguard Total Stock Market Index Fund	3.59M	2.41%	+0	Jul 31, 2026
iShares Russell 2000 ETF	3.03M	2.03%	−13.22K	Jul 31, 2026
Range Nuclear Renaissance Index ETF	2.16M	1.45%	−36.90K	Aug 31, 2026
Vanguard Extended Market Index Fund	1.27M	0.85%	+2.52K	Jul 31, 2026
Fidelity Small Cap Index Fund	1.26M	0.85%	+121.06K	Jun 30, 2026

Insider trades

Form 4 filings by officers, directors and large holders

Over the last 6 months, insiders bought $40.20K (1 trade) and sold $4.90M (16 trades) of ASPI on the open market.

Latest ASPI insider transactions
Insider	Date	Type	Shares	Price	Value
Ainscow Robert	Oct 14, 2026	Sale	22.50K	$2.11	$47.57K
Ryan Robert John Andrew	Sep 30, 2026	Buy	15.00K	$2.68	$40.20K
Ainscow Robert	Sep 8, 2026	Sale	8.44K	$4.29	$36.22K
Mann Paul Elliot	Sep 4, 2026	Sale	83.76K	$4.10	$343.41K
Mann Paul Elliot	Sep 3, 2026	Sale	83.76K	$3.92	$328.33K
Ainscow Donald George	Sep 2, 2026	Sale	23.68K	$3.89	$92.11K
Ainscow Robert	Sep 2, 2026	Sale	25.00K	$3.90	$97.62K
Mann Paul Elliot	Sep 2, 2026	Sale	83.76K	$3.91	$327.49K
Kiessling Heather	Jul 1, 2026	Sale	23.12K	$6.28	$145.22K
Ainscow Donald George	Jun 30, 2026	Sale	100.00K	$6.14	$614.00K

Short interest

Settled Sep 30, 2026

Shares short: 26.46M
Days to cover: 5.31
% of shares outstanding: 17.75%
Average daily volume: 4.98M
Change since last report: +1.5%

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