Quantumsphere Acquisition Corp

QUMS

Exchange: Nasdaq
Industry: Blank Checks
SEC CIK: 0002070900

SEC filings (opens in a new tab)

No open-market purchases or sales by Quantumsphere Acquisition Corp insiders were filed in the last 90 days; 27 institutions reported holding it in 13F filings for Q2 2026, worth $80.3M in total; no superinvestor holds it.

Other share classesQUMSR QUMSU

Q4 2025 vs. Q3 2025

How the institutions holding Quantumsphere Acquisition Corp changed between Q3 2025 and Q4 2025.

All holders in Q4 2025 All holders in Q3 2025

13F holders of QUMS: Q3 2025 compared with Q4 2025
Measure	Q3 2025	Q4 2025	Change
Holders	4	25	+21
Shares	851.3K	6.57M	+5.72M (+671.6%)
Value	$8.48M	$65.7M	+$57.2M (+674.7%)

New holders (22)

Institutions that held Quantumsphere Acquisition Corp at the end of Q4 2025 but not at the end of Q3 2025.

Institutions new to QUMS in Q4 2025
Institution	Shares	Value	% of portfolio
Mizuho Securities USA LLC	718,086	$7.13M	0.12%
Wolverine Asset Management LLC	575,222	$5.76M	0.08%
Karpus Management, Inc.	494,350	$4.95M	0.15%
Shaolin Capital Management LLC	480,000	$4.80M	0.18%
Glazer Capital, LLC	424,153	$4.25M	0.11%
D. E. Shaw & Co., Inc.	409,860	$4.10M	0.00%
Linden Advisors LP	400,000	$4.00M	0.02%
CNH Partners LLC	322,660	$3.23M	0.07%
Berkley W R Corp	303,580	$3.04M	0.17%
HGC Investment Management Inc.	300,000	$3.00M	0.64%
Westchester Capital Management, LLC	250,000	$2.50M	0.12%
Two Sigma Investments, LP	217,479	$2.18M	0.00%
Toronto Dominion Bank	175,778	$1.76M	0.00%
Cable Car Capital LLC	174,801	$1.75M	0.11%
Heights Capital Management, Inc	150,000	$1.50M	0.57%
Radcliffe Capital Management, L.P.	150,000	$1.50M	0.08%
Periscope Capital Inc.	125,000	$1.25M	0.24%
BNP Paribas Arbitrage, SA	102,340	$1.02M	0.00%
Schonfeld Strategic Advisors LLC	55,000	$550.5K	0.00%
Warberg Asset Management LLC	41,421	$414.6K	0.12%
Logan Stone Capital, LLC	14,500	$145.1K	0.04%
Morgan Stanley	30	$300	0.00%

Sold out (1)

Institutions that held Quantumsphere Acquisition Corp at the end of Q3 2025 and filed for Q4 2025 without it.

Institutions that sold out of QUMS in Q4 2025
Institution	Shares, Q3 2025	Value, Q3 2025
Highbridge Capital Management LLC	600,000	$5.98M