Quantumsphere Acquisition Corp
QUMSU- Exchange
- Nasdaq
- Industry
- Blank Checks
- SEC CIK
- 0002070900
No open-market purchases or sales by Quantumsphere Acquisition Corp insiders were filed in the last 90 days; 7 institutions reported holding it in 13F filings for Q2 2026, worth $1.95M in total; no superinvestor holds it.
13F holders, Q1 2026
Institutional positions in Quantumsphere Acquisition Corp as of Mar 31, 2026. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works
- Institutional holders
- 8
- −1 vs. Q4 2025
- Shares held
- 288.3K
- −817.6K (−73.9%) vs. Q4 2025
- Total value
- $2.94M
- −$8.31M (−73.8%) vs. Q4 2025
- New holders
- 1
- 2 more added
- Sold out
- 2
- 1 more reduced
Compare with Q4 2025: new holders, sold out and not filed yet
Holders and value by quarter
Institutions reporting QUMSU on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.
| Quarter | Holders | Value |
|---|---|---|
| Q2 2026 | 7 | $1.95M |
| Q1 2026 | 8 | $2.94M |
| Q4 2025 | 9 | $11.3M |
| Q3 2025 | 30 | $56.7M |
| Q2 2025 | 0 | $0 |
| Q1 2025 | 0 | $0 |
| Q4 2024 | 0 | $0 |
| Q3 2024 | 0 | $0 |
| Q2 2024 | 0 | $0 |
| Q1 2024 | 0 | $0 |
| Q4 2023 | 0 | $0 |
| Q3 2023 | 0 | $0 |
| Q2 2023 | 0 | $0 |
| Q1 2023 | 0 | $0 |
| Q4 2022 | 0 | $0 |
| Q3 2022 | 0 | $0 |
| Q2 2022 | 0 | $0 |
| Q1 2022 | 0 | $0 |
| Q4 2021 | 0 | $0 |
| Q3 2021 | 0 | $0 |
| Q2 2021 | 0 | $0 |
| Q1 2021 | 0 | $0 |
Institutions, Q1 2026
Shares, value and share of portfolio for each institution holding Quantumsphere Acquisition Corp; share changes are against Q4 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Westchester Capital Management, LLC | 100,000 | $1.01M | 0.05% | 00.0% | Unchanged |
| Gabelli & Co Investment Advisers, Inc. | 67,700 | $698.7K | 0.10% | 00.0% | Unchanged |
| Gabelli Funds LLC | 57,300 | $591.3K | 0.00% | 00.0% | Unchanged |
| HRT Financial LP | 30,138 | $304.0K | 0.00% | −951−3.1% | Reduced |
| Clear Street Group Inc. | 22,460 | $231.8K | 0.00% | +7,594+51.1% | Added |
| JPMorgan Chase & Co | 10,000 | $101.5K | 0.00% | 00.0% | Unchanged |
| UBS Group AG | 464 | $4.69K | 0.00% | +5+1.1% | Added |
| Glazer Capital, LLC | 219 | $2.00K | 0.00% | +219 | New |
| Rivernorth Capital Management, LLC | 0 | $0 | 0.00% | −424,512−100.0% | Sold out |
| Polar Asset Management Partners Inc. | 0 | $0 | 0.00% | −400,000−100.0% | Sold out |