QUMS · Quantumsphere Acquisition Corp · Holdings

$10.35 +0.00 (+0.00%) At close · Oct 5

Market Cap

$117.94M

11.41M

Volume · Oct 5 142.08K Avg daily vol (3M) 42.36K

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Use institutional holdings through the 13F API or MCP →

Some SEC filings for this period have not finished importing. Holder totals and changes may be incomplete; these filings remain queued for recovery.

Quarter:

Holders: 35

Total Value: $82,259,896

Total Shares: 14,583,203

Institutional Ownership Trend

4 quarters

Holder Concentration

Across 35 13F filers · Δ vs Mar 31, 2026

Top Holder

11.0%

+1.3 pts

Top 5

39.0%

+1.7 pts

Top 10

64.0%

−0.5 pts

HHI

552

Broadly held+22

Quarterly Activity

vs Mar 31, 2026

New

Increased

Decreased

Sold Out

Unchanged

Holder count: -1

Institutional value: +7.6%

Shares held: -0.4%

Top Buyers

vs Mar 31, 2026

Institution	Added	Now Holds
Mid BERKLEY W R CORP	+361,860	905,510
Small RLH Capital LLC	+150,000	434,900
Mid Westchester Capital Management, LLC	+100,000	450,000
Mid MIZUHO SECURITIES USA LLC	+25,039	757,023
Mid AQR Arbitrage LLC	+7,475	636,771

Top Sellers

vs Mar 31, 2026

Institution	Sold	Now Holds
Small HGC Investment Management Inc.	−300,000	300,000
Mid HIGHBRIDGE CAPITAL MANAGEMENT LLC	−126,559	684,923
Large TORONTO DOMINION BANK	−118,532	817,905
Mid Shaolin Capital Management LLC	−54,860	885,140
Small HEIGHTS CAPITAL MANAGEMENT, INC	−31,213	256,968

Top New Positions

vs Mar 31, 2026

Institution	Acquired	Value (USD)	Open
Mid Quarry LP	75,000	$766,500

Top Sold-Out Positions

vs Mar 31, 2026

Institution	Previously Held	Last Value (USD)	Open
Mega TWO SIGMA INVESTMENTS, LP	35,291	$357,144
Mid Virtu Financial LLC	22,303	$225,706

Filter: New 1 Increased 6 Reduced 15 Sold out 2 Unchanged 13

Showing 59 of 59

All Common Calls Puts

Compact Export CSV

Holder

Value (USD)

% of 13F

BERKLEY W R CORP

$9,007,928

10.95%

881,402

MIZUHO SECURITIES USA LLC

$7,736,775

9.41%

757,023

WOLVERINE ASSET MANAGEMENT LLC

$6,162,496

7.49%

602,984

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Wolverine Holdings, LLC	602,984	$6,162,496	100.0%	Defined

Karpus Management, Inc.

$4,802,122

5.84%

469,875

RIVERNORTH CAPITAL MANAGEMENT, LLC

$4,334,547

5.27%

424,124

D. E. Shaw & Co., Inc.

$4,188,769

5.09%

409,860

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
D. E. SHAW & CO, L.P.	409,860	$4,188,769	100.0%	Defined

Shaolin Capital Management LLC

$4,146,877

5.04%

405,761

GLAZER CAPITAL, LLC

$4,088,909

4.97%

400,089

Linden Advisors LP

$4,088,000

4.97%

400,000

Polar Asset Management Partners Inc.

$4,088,000

4.97%

400,000

HIGHBRIDGE CAPITAL MANAGEMENT LLC

$3,859,143

4.69%

377,607

Westchester Capital Management, LLC

$3,576,999

4.35%

350,000

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
WESTCHESTER CAPITAL PARTNERS, LLC	3,193	$32,632	0.9%	Sole
Virtus Investment Advisers, LLC	317,969	$3,249,643	90.8%	Other
Held directly	28,838	$294,724	8.2%	Sole

AQR Arbitrage LLC

$3,193,985

3.88%

312,523

RLH Capital LLC

$2,555,000

3.11%

250,000

Hudson Bay Capital Management LP

$2,401,700

2.92%

235,000

Cable Car Capital, LP

$1,786,466

2.17%

174,801

Clear Street Group Inc.

$1,684,184

2.05%

164,793

Radcliffe Capital Management, L.P.

$1,533,000

1.86%

150,000

HEIGHTS CAPITAL MANAGEMENT, INC

$1,533,000

1.86%

150,000

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
CVI Investments, Inc.	150,000	$1,533,000	100.0%	Other

BNP PARIBAS ARBITRAGE, SA

$1,175,790

1.43%

115,048

Crossingbridge Advisors, LLC

$1,101,971

1.34%

107,825

TORONTO DOMINION BANK

$1,022,000

1.24%

100,000

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
TD SECURITIES (USA) LLC	100,000	$1,022,000	100.0%	Defined

Periscope Capital Inc.

$766,500

0.93%

75,000

Quarry LP

$766,500

0.93%

75,000

GABELLI & Co INVESTMENT ADVISERS, INC. QUMSU

$699,341

0.85%

67,700

GABELLI FUNDS LLC QUMSU

$591,909

0.72%

57,300

Schonfeld Strategic Advisors LLC

$562,100

0.68%

55,000

HRT FINANCIAL LP QUMSU

$309,900

0.38%

30,000

Clear Street Group Inc. QUMSU

$239,056

0.29%

23,142

Logan Stone Capital, LLC

$148,138

0.18%

14,495

JPMORGAN CHASE & CO QUMSU

$103,300

0.13%

10,000

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
J.P. Morgan Securities LLC	10,000	$103,300	100.0%	Defined

UBS Group AG QUMSU

$4,948

0.01%

479

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
UBS Securities LLC	479	$4,948	100.0%	Defined

MORGAN STANLEY

$541

0.00%

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
MORGAN STANLEY CAPITAL SERVICES, LLC	53	$541	100.0%	Defined

GLAZER CAPITAL, LLC QUMSU

0.00%

221

Shaolin Capital Management LLC QUMSR

—

479,379

Cable Car Capital, LP QUMSR

—

174,801

GLAZER CAPITAL, LLC QUMSR

—

420,536

Harraden Circle Investments, LLC QUMSR

—

993,926

WOLVERINE ASSET MANAGEMENT LLC QUMSR

—

132,552

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Wolverine Holdings, LLC	132,552	$0	—	Defined

Polar Asset Management Partners Inc. QUMSR

—

400,000

Westchester Capital Management, LLC QUMSR

—

100,000

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
WESTCHESTER CAPITAL PARTNERS, LLC	937	$0	—	Sole
Virtus Investment Advisers, LLC	90,801	$0	—	Other
Held directly	8,262	$0	—	Sole

BERKLEY W R CORP QUMSR

—

24,108

RLH Capital LLC QUMSR

—

184,900

BNP PARIBAS ARBITRAGE, SA QUMSR

—

102,340

Periscope Capital Inc. QUMSR

—

125,000

D. E. Shaw & Co., Inc. QUMSR

—

125,000

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
D. E. SHAW & CO, L.P.	125,000	$0	—	Defined

Linden Advisors LP QUMSR

—

400,000

Hudson Bay Capital Management LP QUMSR

—

150,000

Clear Street Group Inc. QUMSR

—

222,380

UBS Group AG QUMSR

—

16,027

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
UBS Securities LLC	16,027	$0	—	Defined

BOOTHBAY FUND MANAGEMENT, LLC QUMSR

—

100,000

Schonfeld Strategic Advisors LLC QUMSR

—

54,200

HEIGHTS CAPITAL MANAGEMENT, INC QUMSR

—

106,968

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
CVI Investments, Inc.	106,968	$0	—	Other

RIVERNORTH CAPITAL MANAGEMENT, LLC QUMSR

—

424,512

TORONTO DOMINION BANK QUMSR

—

717,905

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
TD SECURITIES (USA) LLC	717,905	$0	—	Defined

HIGHBRIDGE CAPITAL MANAGEMENT LLC QUMSR

—

307,316

AQR Arbitrage LLC QUMSR

—

324,248

HGC Investment Management Inc. QUMSR

—

300,000

Radcliffe Capital Management, L.P. QUMSR

—

150,000

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Virtu Americas LLC	22,303	$225,706	100.0%	Defined

Key facts CIK 2070900 CUSIP G7387B106