QUANTUM CORP /DE/ - QMCO
Detailed investor-level table based on 13F positions.
Methodology:
Market value and % of portfolio use SEC reported VALUE ($000).
For PUT/CALL positions this reflects reported underlying exposure, not premium cash paid/received.
Details.
Rows: 0
| Investor | History | Status | Shares held | Market value ($000) | % of portfolio | Previous % | Rank | Change in shares | % change in shares | Source | Date reported |
|---|---|---|---|---|---|---|---|---|---|---|---|
| VANGUARD GROUP INC | History | No change | 625,538 | 4,034 | 0.0% | 0.0% | 1 | 0 | 0.0% | Q4 2025 | Jan 29, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | History | New | 539,275 | 2,561 | 0.0% | — | 2 | +539,275 | New | Q1 2026 | May 15, 2026 |
| BlackRock, Inc. | History | Reduced | 217,532 | 1,033 | 0.0% | 0.0% | 3 | -3,214 | -1.46% | Q1 2026 | May 13, 2026 |
| GEODE CAPITAL MANAGEMENT, LLC | History | Added to | 159,179 | 756 | 0.0% | 0.0% | 4 | +2,308 | 1.47% | Q1 2026 | May 15, 2026 |
| Cygnus Capital Advisors, LLC | History | Added to | 124,086 | 590 | 0.4% | 0.33% | 5 | +54,663 | 78.74% | Q1 2026 | May 12, 2026 |
| UBS Group AG | History | Reduced | 99,068 | 470 | 0.0% | 0.0% | 6 | -66,770 | -40.26% | Q1 2026 | May 05, 2026 |
| VANGUARD FIDUCIARY TRUST CO | History | New | 80,263 | 381 | 0.0% | — | 7 | +80,263 | New | Q1 2026 | May 08, 2026 |
| STATE STREET CORP | History | Reduced | 72,814 | 345 | 0.0% | 0.0% | 8 | -17,900 | -19.73% | Q1 2026 | May 15, 2026 |
| SONA ASSET MANAGEMENT (US) LLC | History | New | 70,092 | 332 | 0.01% | — | 9 | +70,092 | New | Q1 2026 | May 15, 2026 |
| AlphaQuest LLC | History | No change | 29,386 | 189 | 0.01% | 0.01% | 10 | 0 | 0.0% | Q4 2025 | Feb 09, 2026 |
| MARSHALL WACE, LLP | History | Added to | 37,528 | 178 | 0.0% | 0.0% | 11 | +15,788 | 72.62% | Q1 2026 | May 14, 2026 |
| NORTHERN TRUST CORP | History | No change | 28,762 | 136 | 0.0% | 0.0% | 12 | 0 | 0.0% | Q1 2026 | May 14, 2026 |
| LPL Financial LLC | History | Added to | 24,598 | 116 | 0.0% | 0.0% | 13 | +6,234 | 33.95% | Q1 2026 | May 06, 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ | History | Added to | 21,801 | 104 | 0.0% | 0.0% | 14 | +5,900 | 37.1% | Q1 2026 | May 15, 2026 |
| BANK OF AMERICA CORP /DE/ | History | Reduced | 20,485 | 97 | 0.0% | 0.0% | 15 | -50 | -0.24% | Q1 2026 | May 15, 2026 |
| FLAGSHIP HARBOR ADVISORS, LLC | History | Reduced | 17,185 | 81 | 0.0% | 0.01% | 16 | -9,400 | -35.36% | Q1 2026 | Apr 28, 2026 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | History | New | 16,240 | 77 | 0.0% | — | 17 | +16,240 | New | Q1 2026 | May 15, 2026 |
| MORGAN STANLEY | History | Added to | 15,179 | 72 | 0.0% | 0.0% | 18 | +10,866 | 251.94% | Q1 2026 | May 15, 2026 |
| Kovack Advisors, Inc. | History | New | 12,480 | 62 | 0.0% | — | 19 | +12,480 | New | Q1 2026 | May 12, 2026 |
| BARCLAYS PLC | History | Reduced | 12,443 | 59 | 0.0% | 0.0% | 20 | -1,754 | -12.35% | Q1 2026 | May 14, 2026 |
| R Squared Ltd | History | New | 12,245 | 58 | 0.03% | — | 21 | +12,245 | New | Q1 2026 | Apr 29, 2026 |
| XTX Topco Ltd | History | Reduced | 11,321 | 53 | 0.0% | 0.0% | 22 | -627 | -5.25% | Q1 2026 | May 15, 2026 |
| Vanguard Global Advisers, LLC | History | New | 6,000 | 28 | 0.0% | — | 23 | +6,000 | New | Q1 2026 | May 08, 2026 |
| WELLS FARGO & COMPANY/MN | History | Added to | 4,125 | 19 | 0.0% | 0.0% | 24 | +600 | 17.02% | Q1 2026 | May 11, 2026 |
| HOLLENCREST CAPITAL MANAGEMENT | History | New | 2,000 | 9 | 0.0% | — | 26 | +2,000 | New | Q1 2026 | May 07, 2026 |
| SBI Securities Co., Ltd. | History | Reduced | 2,004 | 9 | 0.0% | 0.0% | 25 | -421 | -17.36% | Q1 2026 | Apr 27, 2026 |
| JONES FINANCIAL COMPANIES LLLP | History | Reduced | 1,467 | 6 | 0.0% | 0.0% | 27 | -374 | -20.32% | Q1 2026 | May 15, 2026 |
| OSAIC HOLDINGS, INC. | History | Added to | 965 | 4 | 0.0% | 0.0% | 28 | +217 | 29.01% | Q1 2026 | May 15, 2026 |
| FEDERATED HERMES, INC. | History | Added to | 835 | 3 | 0.0% | 0.0% | 29 | +334 | 66.67% | Q1 2026 | May 11, 2026 |
| BNP PARIBAS FINANCIAL MARKETS | History | Reduced | 261 | 1 | 0.0% | 0.0% | 31 | -758 | -74.39% | Q1 2026 | May 12, 2026 |
| ROYAL BANK OF CANADA | History | Reduced | 128 | 1 | 0.0% | 0.0% | 30 | -705 | -84.63% | Q1 2026 | May 15, 2026 |
| Portolan Capital Management, LLC | History | Closed out | 0 | 0 | — | 0.16% | — | -477,214 | -100.0% | Q1 2026 | May 15, 2026 |
| Engineers Gate Manager LP | History | Closed out | 0 | 0 | — | 0.0% | — | -16,407 | -100.0% | Q1 2026 | May 15, 2026 |
| CITIGROUP INC | History | Closed out | 0 | 0 | — | 0.0% | — | -12,828 | -100.0% | Q1 2026 | May 11, 2026 |
| MILLENNIUM MANAGEMENT LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -11,244 | -100.0% | Q1 2026 | May 15, 2026 |
| NBC SECURITIES, INC. | History | Closed out | 0 | 0 | — | 0.0% | — | -4,000 | -100.0% | Q1 2026 | Apr 14, 2026 |
| Tower Research Capital LLC (TRC) | History | Closed out | 0 | 0 | — | 0.0% | — | -582 | -100.0% | Q1 2026 | May 15, 2026 |
| Quattro Advisors LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -400 | -100.0% | Q1 2026 | May 14, 2026 |
| FIFTH THIRD BANCORP | History | Closed out | 0 | 0 | — | 0.0% | — | -295 | -100.0% | Q1 2026 | May 01, 2026 |
| Rialto Wealth Management, LLC | History | New | 87 | 0 | — | — | — | +87 | New | Q1 2026 | May 14, 2026 |
| Avion Wealth | History | Closed out | 0 | 0 | — | — | — | -68 | -100.0% | Q1 2026 | May 01, 2026 |
| Lavaca Capital LLC | History | New | 39 | 0 | — | — | — | +39 | New | Q1 2026 | May 13, 2026 |
| NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO | History | Closed out | 0 | 0 | — | — | — | -15 | -100.0% | Q1 2026 | May 07, 2026 |
| JPMORGAN CHASE & CO | History | No change | 8 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | May 13, 2026 |
| NATIONAL BANK OF CANADA /FI/ | History | No change | 100 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | May 14, 2026 |
| Global Retirement Partners, LLC | History | No change | 65 | 0 | — | — | — | 0 | 0.0% | Q4 2025 | Feb 06, 2026 |
| Activest Wealth Management | History | No change | 1 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | Apr 15, 2026 |
| Farther Finance Advisors, LLC | History | No change | 4 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | Apr 07, 2026 |
| Federation des caisses Desjardins du Quebec | History | No change | 25 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | May 13, 2026 |
| EFG International AG | History | No change | 100 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | May 15, 2026 |