Quantumsphere Acquisition QUMS Institutional Ownership

NASDAQ QUMS

$10.33 +0.00 (+0.00%)

At close: Sep 18, 2026 · 4:00 PM EDT

Institutions by Trading Activity

27 Institutions

Increased 6 22.2%

Unchanged 11 40.7%

Reduced 10 37.0%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

53.90%

▼-37.50 pp QoQ

Shares Held by Institutions

7.83Mn

of 14.53Mn outstanding

▲+8.83% QoQ

Shares Outstanding

14.53Mn

6.70Mn held outside 13F filers

Institutional Investors

filed 13F for Jun 2026

▼-3 vs prior quarter

Net Shares Added (QoQ)

+635.24K

accumulated since last quarter

Value of Holdings

$80.92Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Quarter ending 30 Jun, 2026

Quantumsphere Acquisition Corp (NASDAQ:QUMS) showed up in the 13F filings of 27 institutional investors as of June 2026.

Their combined ownership stood at 53.9% of outstanding shares in June 2026, down from 91.4% in March 2026.
Their total shares held in QUMS increased 8.83% from the prior quarter, while the number of investors in Quantumsphere Acquisition stayed flat year over year.
Activity in QUMS broke down as 6 buyers, 10 sellers, and 11 unchanged among 27 total holders.
Combined, these investors held 7.83Mn shares in QUMS for June 2026, up by 635.24K shares quarter on quarter, and with no net change year over year.
Berkley W R Corp is the top holder of Quantumsphere Acquisition as of June 30, 2026, with 881.4K shares representing 6.06% of outstanding stock.
Top purchasers of QUMS stock for the quarter ending June 2026 included Berkley W R Corp (372.86K), HIGHBRIDGE CAPITAL MANAGEMENT LLC (256.53K), RLH Capital LLC (150.0K), Westchester Capital Management, LLC (100.0K), Quarry LP (75.0K).
The largest sellers of Quantumsphere Acquisition for the quarter ending June 2026 were Toronto Dominion Bank (165.6K), Shaolin Capital Management LLC (74.24K), PERISCOPE CAPITAL INC. (25.0K), Karpus Management, Inc. (24.0K), GLAZER CAPITAL, LLC (22.93K).
Business Quant data shows the 10 biggest positions in Quantumsphere Acquisition as of June 2026 are held by Berkley W R Corp (881.4K), MIZUHO SECURITIES USA LLC (731.98K), WOLVERINE ASSET MANAGEMENT LLC (602.98K), Karpus Management, Inc. (469.88K), RIVERNORTH CAPITAL MANAGEMENT, LLC (424.12K), D. E. Shaw & Co., Inc. (409.86K), Shaolin Capital Management LLC (405.76K), GLAZER CAPITAL, LLC (400.09K), LINDEN ADVISORS LP (400.0K), Polar Asset Management Partners Inc. (400.0K).

Form 13F Holdings

27 Institutional Holders

Report period 30 Jun, 2026

Total shares held 7.83Mn

Of outstanding 53.90%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	Berkley W R Corp	0000011544	881,402	6.06%	▲372,862	+73.32%	$9.01Mn
2	MIZUHO SECURITIES USA LLC	0000812291	731,984	5.04%	0	0.00%	$7.36Mn
3	WOLVERINE ASSET MANAGEMENT LLC	0001279891	602,984	4.15%	▼1,000	-0.17%	$6.16Mn
4	Karpus Management, Inc.	0001048703	469,875	3.23%	▼24,000	-4.86%	$4.80Mn
5	RIVERNORTH CAPITAL MANAGEMENT, LLC	0001447578	424,124	2.92%	▼388	-0.09%	$4.37Mn
6	D. E. Shaw & Co., Inc.	0001009207	409,860	2.82%	0	0.00%	$4.19Mn
7	Shaolin Capital Management LLC	0001766806	405,761	2.79%	▼74,239	-15.47%	$4.15Mn
8	GLAZER CAPITAL, LLC	0001076809	400,089	2.75%	▼22,930	-5.42%	$4.09K
9	LINDEN ADVISORS LP	0001279396	400,000	2.75%	0	0.00%	$4.09Mn
9	Polar Asset Management Partners Inc.	0001326389	400,000	2.75%	0	0.00%	$4.09Mn
10	HIGHBRIDGE CAPITAL MANAGEMENT LLC	0000919185	377,607	2.60%	▲256,529	+211.87%	$3.87Mn
11	Westchester Capital Management, LLC	0001512805	350,000	2.41%	▲100,000	+40.00%	$3.58Mn
12	AQR Arbitrage LLC	0001167456	312,523	2.15%	▲4,229	+1.37%	$3.19Mn
13	RLH Capital LLC	0002008031	250,000	1.72%	▲150,000	+150.00%	$2.56Mn
14	Hudson Bay Capital Management LP	0001393825	235,000	1.62%	0	0.00%	$2.40Mn
15	Cable Car Capital, LP	0001699575	174,801	1.20%	0	0.00%	$1.79Mn
16	Clear Street Group Inc.	0001881567	164,793	1.13%	▼10,208	-5.83%	$1.68Mn
17	HEIGHTS CAPITAL MANAGEMENT, INC	0001081698	150,000	1.03%	0	0.00%	$1.53Mn
17	Radcliffe Capital Management, L.P.	0001218275	150,000	1.03%	0	0.00%	$1.53Mn
18	BNP PARIBAS FINANCIAL MARKETS	0001166588	115,048	0.79%	0	0.00%	$1.18Mn

Showing 1 to 20 of 27 holders