# QUANTUMSPHERE ACQUISITION CO (QUMSR)

> Institutional ownership reported to the SEC as of Q2 2026, from Form 13F filings. Source: https://holderbook.com/stocks/QUMSR/

- Reporting holders: 25
- Reported value: $1.2M
- Shares held by institutions: 6,536,098 of 10,936,105 outstanding
- Held through calls: 0.0%
- Held through puts: 0.0%

A 13F reports long US equity positions only. Shorts, bonds, foreign listings and cash are not visible here, and positions are disclosed up to 45 days after the quarter ends.

## Largest holders

| Manager | Value | Shares | Share of their book | Quarters held |
|---|---|---|---|---|
| [Harraden Circle Investments, LLC](https://holderbook.com/funds/1910592-harraden-circle-investments-llc/) | $197.8K | 993,926 | 0.0% | 4 |
| [TORONTO DOMINION BANK](https://holderbook.com/funds/947263-toronto-dominion-bank/) | $142.9K | 717,905 | 0.0% | 4 |
| [Shaolin Capital Management LLC](https://holderbook.com/funds/1766806-shaolin-capital-management-llc/) | $95.4K | 479,379 | 0.0% | 3 |
| [GLAZER CAPITAL, LLC](https://holderbook.com/funds/1076809-glazer-capital-llc/) | $68.0K | 420,536 | 0.0% | 3 |
| [RIVERNORTH CAPITAL MANAGEMENT, LLC](https://holderbook.com/funds/1447578-rivernorth-capital-management-llc/) | $65.8K | 424,512 | 0.0% | 2 |
| [AQR Arbitrage LLC](https://holderbook.com/funds/1167456-aqr-arbitrage-llc/) | $64.5K | 324,248 | 0.0% | 3 |
| [Linden Advisors LP](https://holderbook.com/funds/1279396-linden-advisors-lp/) | $64.3K | 400,000 | 0.0% | 3 |
| [Polar Asset Management Partners Inc.](https://holderbook.com/funds/1326389-polar-asset-management-partners-inc/) | $64.3K | 400,000 | 0.0% | 2 |
| [HGC Investment Management Inc.](https://holderbook.com/funds/1711200-hgc-investment-management-inc/) | $59.7K | 300,000 | 0.0% | 3 |
| [HIGHBRIDGE CAPITAL MANAGEMENT LLC](https://holderbook.com/funds/919185-highbridge-capital-management-llc/) | $52.2K | 307,316 | 0.0% | 4 |
| [Clear Street Group Inc.](https://holderbook.com/funds/1881567-clear-street-group-inc/) | $44.3K | 222,380 | 0.0% | 3 |
| [Cable Car Capital, LP](https://holderbook.com/funds/1699575-cable-car-capital-lp/) | $34.8K | 174,801 | 0.0% | 3 |
| [RLH Capital LLC](https://holderbook.com/funds/2008031-rlh-capital-llc/) | $29.7K | 184,900 | 0.0% | 2 |
| [WOLVERINE ASSET MANAGEMENT LLC](https://holderbook.com/funds/1279891-wolverine-asset-management-llc/) | $26.4K | 132,552 | 0.0% | 3 |
| [Hudson Bay Capital Management LP](https://holderbook.com/funds/1393825-hudson-bay-capital-management-lp/) | $25.5K | 150,000 | 0.0% | 4 |
| [Radcliffe Capital Management, L.P.](https://holderbook.com/funds/1218275-radcliffe-capital-management-l-p/) | $24.1K | 150,000 | 0.0% | 3 |
| [HEIGHTS CAPITAL MANAGEMENT, INC](https://holderbook.com/funds/1081698-heights-capital-management-inc/) | $21.3K | 106,968 | 0.0% | 3 |
| [D. E. Shaw & Co., Inc.](https://holderbook.com/funds/1009207-d-e-shaw-co-inc/) | $21.2K | 125,000 | 0.0% | 3 |
| [Periscope Capital Inc.](https://holderbook.com/funds/1695320-periscope-capital-inc/) | $20.1K | 125,000 | 0.0% | 3 |
| [BNP PARIBAS FINANCIAL MARKETS](https://holderbook.com/funds/1166588-bnp-paribas-financial-markets/) | $16.4K | 102,340 | 0.0% | 3 |
| [BOOTHBAY FUND MANAGEMENT, LLC](https://holderbook.com/funds/1549230-boothbay-fund-management-llc/) | $16.1K | 100,000 | 0.0% | 3 |
| [Westchester Capital Management, LLC](https://holderbook.com/funds/1512805-westchester-capital-management-llc/) | $12.2K | 100,000 | 0.0% | 1 |
| [Schonfeld Strategic Advisors LLC](https://holderbook.com/funds/1665241-schonfeld-strategic-advisors-llc/) | $8.7K | 54,200 | 0.0% | 3 |
| [BERKLEY W R CORP](https://holderbook.com/funds/11544-berkley-w-r-corp/) | $3.9K | 24,108 | 0.0% | 3 |
| [UBS Group AG](https://holderbook.com/funds/1610520-ubs-group-ag/) | $2.0K | 16,027 | 0.0% | 3 |

## Quarter by quarter

| Quarter | Holders | Reported value |
|---|---|---|
| Q2 2026 | 25 | $1.2M |
| Q1 2026 | 24 | $1.6M |
| Q4 2025 | 23 | $1.2M |
| Q3 2025 | 4 | $224.0K |