Quantumsphere AcquisitionQUMSRPreferred / convertible
13F holders, Q1 2026 (March 31)24holders +1
2new positions
2sold out
1famous investor
$0.24avg. 13F price*
At the end of Q1 2026, 24 institutions reported holding Quantumsphere Acquisition Co. (QUMSR) in their 13F filings, up 1 from Q4 2025. 2 opened new positions and 2 sold out. The largest holders were Harraden Circle Investments, LLC ($248K), Highbridge Capital Management LLC ($173K) and Toronto Dominion Bank ($168K). One famous investor held it David E. Shaw ( of D. E. Shaw & Co.'s portfolio).
- Company
- Quantumsphere Acquisition Co.
- CUSIP
- G7387B114
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q4 2025 → Q1 2026
| Institutions | Total Value | |
|---|---|---|
| New Positions | 2 | $206K |
| Exits | 2 | $8K |
All 13F filers, Q4 2025 → Q1 2026: 830,879 shares bought and 93,733 shares sold, net +737,146 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 24 holders
| Harraden Circle Investments, LLC | — | No change | 993,926 | $248K |
| Highbridge Capital Management LLC | — | Add +0.9% | 690,404 | $173K |
| Toronto Dominion Bank | — | Reduce -3.5% | 670,837 | $168K |
| Shaolin Capital Management LLC | — | No change | 460,000 | $115K |
| Rivernorth Capital Management, LLC | — | New | 424,512 | $106K |
| Polar Asset Management Partners Inc. | — | New | 400,000 | $100K |
| Linden Advisors LP | — | No change | 400,000 | $90K |
| AQR Arbitrage LLC | — | Reduce -0.5% | 321,002 | $80K |
| HGC Investment Management Inc. | — | No change | 300,000 | $75K |
| Glazer Capital, LLC | — | No change | 420,536 | $67K |
| Clear Street Group Inc. | — | Reduce -2.1% | 224,380 | $56K |
| Cable Car Capital, LP | — | No change | 174,801 | $44K |
| RLH Capital LLC | — | — | 184,900 | $41K |
| Hudson Bay Capital Management LP | — | No change | 150,000 | $38K |
| Heights Capital Management, Inc. | — | Reduce -7.8% | 138,181 | $35K |
| Wolverine Asset Management LLC | — | Reduce -9.9% | 135,213 | $34K |
| Radcliffe Capital Management, L.P. | — | No change | 150,000 | $33K |
| D. E. Shaw & Co. | — | No change | 125,000 | $31K |
| Periscope Capital Inc. | — | No change | 125,000 | $28K |
| Boothbay Fund Management, LLC | — | No change | 100,000 | $25K |
| BNP Paribas Financial Markets | — | No change | 102,340 | $23K |
| Schonfeld Strategic Advisors LLC | — | Reduce -0.2% | 54,500 | $12K |
| Berkley W R Corp. | — | No change | 35,110 | $8K |
| UBS Group AG | — | Reduce -0.5% | 16,027 | $3K |
"% of holder's portfolio" is QUMSR's weight in each manager's 13F, not the share of Quantumsphere Acquisition Co. the manager owns.