QUANTUMSPHERE ACQUISITION CO (QUMS)
Institutional ownership reported to the SEC as of Q2 2026, across 4 quarters.
Institutions report 8,190,158 shares against 10,936,105 outstanding. Shares only - option lines are excluded, which is why this can be compared with the company at all. The count comes from the cover page of the company's own most recent report, so it is dated when that was filed rather than at quarter end.
Options share is the part of reported value carried in derivative lines rather than shares. A high figure means institutions are expressing a view on this security without owning much of it.
Holders
| Filer | Value | Shares | Their book | Held | Change |
|---|---|---|---|---|---|
| MIZUHO SECURITIES USA LLC | $15.0M | 1,489,007 | 0.14% | 3q | +103.4%+$7.6M |
| BERKLEY W R CORP | $9.0M | 881,402 | 0.43% | 3q | +73.3%+$3.8M |
| WOLVERINE ASSET MANAGEMENT LLC | $6.2M | 602,984 | 0.05% | 3q | HELD |
| Karpus Management, Inc. | $4.8M | 469,875 | 0.14% | 3q | -4.9%-$245.3K |
| RIVERNORTH CAPITAL MANAGEMENT, LLC | $4.4M | 424,124 | 0.21% | 2q | HELD |
| D. E. Shaw & Co., Inc. | $4.2M | 409,860 | 0.00% | 3q | HELD |
| Shaolin Capital Management LLC | $4.1M | 405,761 | 0.20% | 3q | -15.5%-$758.7K |
| Linden Advisors LP | $4.1M | 400,000 | 0.02% | 3q | HELD |
| Polar Asset Management Partners Inc. | $4.1M | 400,000 | 0.07% | 2q | HELD |
| HIGHBRIDGE CAPITAL MANAGEMENT LLC | $3.9M | 377,607 | 0.09% | 2q | +211.9%+$2.6M |
| Westchester Capital Management, LLC | $3.6M | 350,000 | 0.18% | 3q | +40.0%+$1.0M |
| AQR Arbitrage LLC | $3.2M | 312,523 | 0.05% | 3q | +1.4%+$43.2K |
| RLH Capital LLC | $2.6M | 250,000 | 1.22% | 2q | +150.0%+$1.5M |
| Hudson Bay Capital Management LP | $2.4M | 235,000 | 0.01% | 4q | HELD |
| Cable Car Capital, LP | $1.8M | 174,801 | 0.04% | 3q | HELD |
| Clear Street Group Inc. | $1.7M | 164,793 | 0.00% | 4q | -5.8%-$104.3K |
| HEIGHTS CAPITAL MANAGEMENT, INC | $1.5M | 150,000 | 0.35% | 3q | HELD |
| Radcliffe Capital Management, L.P. | $1.5M | 150,000 | 0.12% | 3q | HELD |
| BNP PARIBAS FINANCIAL MARKETS | $1.2M | 115,048 | 0.00% | 3q | HELD |
| Crossingbridge Advisors, LLC | $1.1M | 107,825 | 0.19% | 2q | HELD |
| TORONTO DOMINION BANK | $1.0M | 100,000 | 0.00% | 3q | -62.3%-$1.7M |
| Periscope Capital Inc. | $766.5K | 75,000 | 0.07% | 3q | -25.0%-$255.5K |
| Quarry LP | $766.5K | 75,000 | 0.06% | new | NEW |
| Schonfeld Strategic Advisors LLC | $562.1K | 55,000 | 0.00% | 3q | HELD |
| Logan Stone Capital, LLC | $148.1K | 14,495 | 0.03% | 3q | HELD |
| GLAZER CAPITAL, LLC | $4.1K | 400,089 | 0.10% | 3q | -5.4% |
| MORGAN STANLEY | $542 | 53 | 0.00% | 3q | -15.9% |
Five percent filings
Anyone crossing 5% of a company must say so within days - far sooner than the next quarterly holdings report. A 13D declares an intent to influence the company; a 13G is the passive version. See all activist filings →
| Filed | Form | Filer | % of class |
|---|---|---|---|
| 2026-08-06 | 13G | W. R. Berkley Corporation SPACwith 1 co-filers | 7.7% |
Quarter by quarter
Coverage begins with the quarter ending 2018-12-31. Earlier filings exist only as occasional late amendments, too sparse to describe a market, so they are not shown.
| Quarter | Holders | Value | Shares | New | Added | Trimmed | Options |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 26 | $83.6M | 8,190,158 | 1 | 6 | 6 | 0.0% |
| Q1 2026 | 27 | $71.9M | 7,110,256 | 4 | 6 | 4 | 0.0% |
| Q4 2025 | 23 | $61.2M | 6,119,869 | 21 | 1 | 0 | 0.0% |
| Q3 2025 | 4 | $8.3M | 851,333 | 3 | 0 | 0 | 0.0% |