Who owns Quantumsphere Acquisition Corp?
Prices and market caps: Cboe delayed data, at least 15 minutes delayed. Not real-time. Fundamentals from company filings.
Institutional ownership of QUMS from SEC Form 13F filings across 27 reporting managers. All positions are from one synchronized reporting period — 2026-06-30 books, filed up to 45 days after quarter end — so every row is comparable.
As of the 2026-06-30 reporting period, 27 institutions disclosed 7.8M shares of Quantumsphere Acquisition Corp worth $80.0M — about 94.6% of shares outstanding; the largest disclosed holder is BERKLEY W R CORP. Source: SEC Form 13F filings, parsed by EvidInvest.
27
13F holders
$80.0M
value, 2026 filers
94.6%
of shares outstanding (7.8M sh)
1
new positions (2026 filers)
Top institutional holders
ordered by shares owned · positions as of 2026-06-30 · % of fund = share of the manager's own book · % of co. = share of QUMS's shares outstanding
| # | Manager | Shares | Value | % of fund | % of co. | Δ shares QoQ |
|---|---|---|---|---|---|---|
| 1 | BERKLEY W R CORP | 881,402 | $9.0M | 0.4% | 10.6% | +73.3% |
| 2 | MIZUHO SECURITIES USA LLC | 731,984 | $7.4M | 0.2% | 8.8% | 0.0% |
| 3 | WOLVERINE ASSET MANAGEMENT LLC | 602,984 | $6.2M | 0.1% | 7.3% | -0.2% |
| 4 | Karpus Management, Inc. | 469,875 | $4.8M | 0.1% | 5.7% | -4.9% |
| 5 | RIVERNORTH CAPITAL MANAGEMENT, LLC | 424,124 | $4.4M | 0.2% | 5.1% | -0.1% |
| 6 | D. E. Shaw & Co., Inc. | 409,860 | $4.2M | 0.0% | 5% | 0.0% |
| 7 | Shaolin Capital Management LLC | 405,761 | $4.1M | 0.2% | 4.9% | -15.5% |
| 8 | GLAZER CAPITAL, LLC | 400,089 | $4.1M | 0.1% | 4.8% | -5.4% |
| 9 | Linden Advisors LP | 400,000 | $4.1M | 0.0% | 4.8% | 0.0% |
| 10 | Polar Asset Management Partners Inc. | 400,000 | $4.1M | 0.1% | 4.8% | 0.0% |
| 11 | HIGHBRIDGE CAPITAL MANAGEMENT LLC | 377,607 | $3.9M | 0.1% | 4.6% | +211.9% |
| 12 | Westchester Capital Management, LLC | 350,000 | $3.6M | 0.2% | 4.2% | +40.0% |
| 13 | AQR Arbitrage LLC | 312,523 | $3.2M | 0.0% | 3.8% | +1.4% |
| 14 | RLH Capital LLC | 250,000 | $2.6M | 1.2% | 3% | +150.0% |
| 15 | Hudson Bay Capital Management LP | 235,000 | $2.4M | 0.0% | 2.8% | 0.0% |
| 16 | Cable Car Capital, LP | 174,801 | $1.8M | 0.0% | 2.1% | 0.0% |
| 17 | Clear Street Group Inc. | 164,793 | $1.7M | 0.0% | 2% | -5.8% |
| 18 | Radcliffe Capital Management, L.P. | 150,000 | $1.5M | 0.1% | 1.8% | 0.0% |
| 19 | HEIGHTS CAPITAL MANAGEMENT, INC | 150,000 | $1.5M | 0.4% | 1.8% | 0.0% |
| 20 | BNP PARIBAS FINANCIAL MARKETS | 115,048 | $1.2M | 0.0% | 1.4% | 0.0% |
| 21 | Crossingbridge Advisors, LLC | 107,825 | $1.1M | 0.2% | 1.3% | 0.0% |
| 22 | TORONTO DOMINION BANK | 100,000 | $1.0M | 0.0% | 1.2% | -62.3% |
| 23 | Quarry LPNEW | 75,000 | $766,500 | 0.1% | 0.9% | new |
| 24 | Periscope Capital Inc. | 75,000 | $766,500 | 0.1% | 0.9% | -25.0% |
| 25 | Schonfeld Strategic Advisors LLC | 55,000 | $562,100 | 0.0% | 0.7% | 0.0% |
Source: SEC Form 13F-HR filings (institutional managers over $100M in US-listed positions). 13Fs disclose long positions only, up to 45 days after quarter end; each manager's latest filed quarter is shown per row and dollar values are the manager's filed marks. Aggregates labeled "2026 filers" count only managers whose latest book is a 2026 quarter. Related: valuation · options positioning · supply chain. Research, not investment advice.