8 institutions reported holding $1.9M of QUANTUMSPHERE ACQUISITION CO (QUMSU) in SEC 13F filings for 2026-06-30. Largest institutional holders: GABELLI & Co INVESTMENT ADVISERS, INC. ($699,341), GABELLI FUNDS LLC ($591,909), HRT FINANCIAL LP ($309,000), Clear Street Group Inc. ($239,057), JPMORGAN CHASE & CO ($103,300). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | GABELLI & Co INVESTMENT ADVISERS, INC. | $699,341 | 67,700 | Hold |
| 2 | GABELLI FUNDS LLC | $591,909 | 57,300 | Hold |
| 3 | HRT FINANCIAL LP | $309,000 | 30,000 | Trimmed |
| 4 | Clear Street Group Inc. | $239,057 | 23,142 | Added |
| 5 | JPMORGAN CHASE & CO | $103,300 | 10,000 | Hold |
| 6 | UBS Group AG | $4,948 | 479 | Added |
| 7 | GLAZER CAPITAL, LLC | $2,000 | 221 | Added |
| 8 | Westchester Capital Management, LLC | $0 | 0 | Exited |
Source: SEC Form 13F filings · as of 2026-06-30