$QUMS

$10.40 +$0.00 (0.0%) Close

$QUMS Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 11.4M shares outstanding

Who owns QUMS?

By type of holder

Institutions 74.0% Insiders 0.0% Everyone else 26.0%

Concentration Top 10 holders own 75.5%

Whiteowl Holdings LLC 27.4% · Mizuho Securities USA LLC 13.1%

Institutional ownership

74.0%

+7.8 pts vs last qtr

Institutional holders

-3 vs last qtr

Net shares bought

+884.7K

by institutions in Q2 2026

New / sold out

1 / 4

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Mizuho Securities USA LLC +757.0K
Berkley W R Corp +372.9K

Biggest sellers in Q2 2026

HGC Investment Management Inc. SOLD OUT −300.0K
Toronto Dominion Bank −165.6K

Who is planning to sell?

No insider has filed a notice of proposed sale (Form 144) for Quantumsphere Acquisition Corporation in the last 12 months.

Is your stake being diluted?

There are not yet two fiscal years of reported share counts for Quantumsphere Acquisition Corporation.

How patient are the owners?

Institutional shares by how long they've been held

5+ years0% 3–5 years0% 1–3 years0% Under 1 year100%

Quarterly turnover

16.9%

of institutional shares changed hands

Top 10 managers, median time held

2 quarters

Super Investors

Investment managers reporting QUMS on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
MS Mizuho Securities USA LLC	1.5M	13.05%	+757.0K (+103.4%)	Q4 '25	0.1%
Shares held by quarter Peak holding1.5M (Q2'26) Change over 8 quarters+1.5M Share of the company13.050% Mizuho Securities USA LLC's full portfolio →
BW Berkley W R Corp	881.4K	7.73%	+372.9K (+73.3%)	Q4 '25	0.4%
Shares held by quarter Peak holding881.4K (Q2'26) Change over 8 quarters+881.4K Share of the company7.730% Berkley W R Corp's full portfolio →

Mizuho Securities USA LLC

1.5M

% of company

13.05%

Change vs last qtr

+757.0K (+103.4%)

Held since

Q4 '25

Berkley W R Corp

881.4K

% of company

7.73%

Change vs last qtr

+372.9K (+73.3%)

Held since

Q4 '25

27 more super investors behind a free account

See every manager holding Quantumsphere Acquisition Corporation, how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting QUMS on Form N-PORT; together they hold 1.9% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
RO RiverNorth Opportunities Fund Inc. Rivernorth Opportunities Fund Inc.	$1.02M	100.0K	0.88%	0.31%	June 30, 2026
FT First Trust Alternative Opportunities Fund First Trust Alternative Opportunities Fund	$1.02M	100.0K	0.88%	0.03%	June 30, 2026

RiverNorth Opportunities Fund Inc.

Rivernorth Opportunities Fund Inc.

Position value

$1.02M

% of company

0.88%

% of the fund

0.31%

As of

June 30, 2026

First Trust Alternative Opportunities Fund

Position value

$1.02M

% of company

0.88%

% of the fund

0.03%

As of

June 30, 2026

2 more funds behind a free account

See every fund holding Quantumsphere Acquisition Corporation and how much of the fund the position is.

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
WH Whiteowl Holdings LLC 5%+ holder 13D · 27.4%	3.1M	27.41%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company27.410% Disclosed stake13D · 27.4% View the 13D/G filing →

Whiteowl Holdings LLC

5%+ holder13D · 27.4%

3.1M

% of company

27.41%

Change vs last qtr

—

Held since

—

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