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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Two Seas Capital LP | History | Reduced | 1,490,992 | 47,294 | 0.54% | 0.54% | 1 | -997,543 | -40.09% | Q3 2026 | Oct 06, 2026 |
| Alyeska Investment Group, L.P. | History | No change | 2,653,928 | 29,193 | 0.08% | 0.08% | 2 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| OAKTREE CAPITAL MANAGEMENT LP | History | No change | 2,011,678 | 22,128 | 0.31% | 0.31% | 3 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| UBS Group AG | History | Added to | 460,144 | 14,595 | 0.0% | 0.0% | 4 | +414,038 | 898.01% | Q3 2026 | Nov 10, 2026 |
| Neuberger Berman Group LLC | History | No change | 1,163,315 | 12,796 | 0.01% | 0.01% | 5 | 0 | 0.0% | Q2 2026 | Oct 27, 2026 |
| Portolan Capital Management, LLC | History | No change | 1,020,120 | 11,221 | 0.42% | 0.42% | 6 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| ASHFORD CAPITAL MANAGEMENT INC | History | No change | 1,039,200 | 10,551 | 1.13% | 1.13% | 7 | 0 | 0.0% | Q2 2026 | Aug 21, 2026 |
| GEODE CAPITAL MANAGEMENT, LLC | History | Added to | 305,156 | 9,685 | 0.0% | 0.0% | 8 | +140,556 | 85.39% | Q3 2026 | Nov 06, 2026 |
| MARSHALL WACE, LLP | History | No change | 713,075 | 7,843 | 0.01% | 0.01% | 9 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | History | No change | 605,541 | 6,660 | 0.0% | 0.0% | 10 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| ACADIAN ASSET MANAGEMENT LLC | History | New | 138,893 | 4,403 | 0.01% | — | 11 | +138,893 | New | Q3 2026 | Nov 09, 2026 |
| Manatuck Hill Partners, LLC | History | No change | 350,000 | 3,850 | 1.28% | 1.28% | 12 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| BlackRock, Inc. | History | No change | 273,030 | 3,003 | 0.0% | 0.0% | 13 | 0 | 0.0% | Q2 2026 | Aug 07, 2026 |
| Squarepoint Ops LLC | History | Added to | 88,843 | 2,818 | 0.0% | 0.0% | 14 | +55,026 | 162.72% | Q3 2026 | Nov 09, 2026 |
| SONA ASSET MANAGEMENT (US) LLC | History | No change | 250,100 | 2,751 | 0.06% | 0.06% | 15 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| JANE STREET GROUP, LLC | History | No change | 208,500 | 2,293 | 0.0% | 0.0% | 16 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | History | No change | 200,075 | 2,200 | 0.0% | 0.0% | 17 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Cinctive Capital Management LP | History | No change | 182,769 | 2,010 | 0.07% | 0.07% | 18 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| BANK OF AMERICA CORP /DE/ | History | No change | 170,130 | 1,871 | 0.0% | 0.0% | 19 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| RENAISSANCE TECHNOLOGIES LLC | History | No change | 154,516 | 1,699 | 0.0% | 0.0% | 20 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| CITADEL ADVISORS LLC | History | No change | 136,800 | 1,504 | 0.0% | 0.0% | 21 | 0 | 0.0% | Q2 2026 | Sep 02, 2026 |
| Walleye Capital LLC | History | No change | 120,044 | 1,320 | 0.0% | 0.0% | 22 | 0 | 0.0% | Q2 2026 | Aug 03, 2026 |
| SEI INVESTMENTS CO | History | Added to | 40,374 | 1,280 | 0.0% | 0.0% | 23 | +1,635 | 4.22% | Q3 2026 | Nov 10, 2026 |
| RAYMOND JAMES FINANCIAL INC | History | No change | 103,836 | 1,142 | 0.0% | 0.0% | 24 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Centiva Capital, LP | History | No change | 100,000 | 1,100 | 0.01% | 0.01% | 25 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| BARCLAYS PLC | History | Added to | 31,257 | 991 | 0.0% | 0.0% | 26 | +30,802 | 6769.67% | Q3 2026 | Nov 06, 2026 |
| VANGUARD FIDUCIARY TRUST CO | History | No change | 89,125 | 980 | 0.0% | 0.0% | 27 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| KKM Financial LLC | History | No change | 90,274 | 960 | 0.13% | 0.13% | 28 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Qube Research & Technologies Ltd | History | No change | 80,977 | 890 | 0.0% | 0.0% | 29 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| STATE STREET CORP | History | No change | 75,914 | 835 | 0.0% | 0.0% | 30 | 0 | 0.0% | Q2 2026 | Sep 22, 2026 |
| Cygnus Capital Advisors, LLC | History | No change | 74,323 | 818 | 0.56% | 0.56% | 31 | 0 | 0.0% | Q2 2026 | Sep 03, 2026 |
| Man Group plc | History | No change | 68,593 | 754 | 0.0% | 0.0% | 32 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Informed Momentum Co LLC | History | No change | 64,857 | 713 | 0.06% | 0.06% | 33 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| Y-Intercept (Hong Kong) Ltd | History | New | 21,886 | 694 | 0.02% | — | 34 | +21,886 | New | Q3 2026 | Oct 16, 2026 |
| LANDSCAPE CAPITAL MANAGEMENT, L.L.C. | History | New | 20,262 | 642 | 0.05% | — | 35 | +20,262 | New | Q3 2026 | Nov 10, 2026 |
| Cambridge Investment Research Advisors, Inc. | History | New | 14,126 | 448 | 0.0% | — | 36 | +14,126 | New | Q3 2026 | Nov 02, 2026 |
| BANK OF MONTREAL /CAN/ | History | New | 12,596 | 399 | 0.0% | — | 37 | +12,596 | New | Q3 2026 | Nov 09, 2026 |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC | History | No change | 34,601 | 380 | 0.01% | 0.01% | 38 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| NORTHERN TRUST CORP | History | No change | 33,220 | 365 | 0.0% | 0.0% | 39 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| FLAGSHIP HARBOR ADVISORS, LLC | History | No change | 11,004 | 349 | 0.01% | 0.0% | 40 | 0 | 0.0% | Q3 2026 | Oct 26, 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ | History | No change | 25,069 | 276 | 0.0% | 0.0% | 41 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Jefferies Financial Group Inc. | History | New | 7,700 | 244 | 0.0% | — | 42 | +7,700 | New | Q3 2026 | Nov 05, 2026 |
| MILLENNIUM MANAGEMENT LLC | History | No change | 21,755 | 239 | 0.0% | 0.0% | 43 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| SCOTIA CAPITAL INC. | History | New | 7,449 | 236 | 0.0% | — | 44 | +7,449 | New | Q3 2026 | Nov 10, 2026 |
| LPL Financial LLC | History | New | 7,273 | 230 | 0.0% | — | 45 | +7,273 | New | Q3 2026 | Nov 06, 2026 |
| Calamos Advisors LLC | History | New | 6,770 | 214 | 0.0% | — | 46 | +6,770 | New | Q3 2026 | Nov 02, 2026 |
| TRUE Private Wealth Advisors | History | New | 6,645 | 210 | 0.02% | — | 48 | +6,645 | New | Q3 2026 | Oct 19, 2026 |
| GOLDMAN SACHS GROUP INC | History | No change | 19,153 | 210 | 0.0% | 0.0% | 47 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Bank of New York Mellon Corp | History | New | 6,539 | 207 | 0.0% | — | 49 | +6,539 | New | Q3 2026 | Nov 05, 2026 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | History | No change | 16,240 | 178 | 0.0% | 0.0% | 50 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| MORGAN STANLEY | History | No change | 15,492 | 170 | 0.0% | 0.0% | 51 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| Kovack Advisors, Inc. | History | No change | 13,430 | 146 | 0.01% | 0.01% | 52 | 0 | 0.0% | Q2 2026 | Jul 28, 2026 |
| Schonfeld Strategic Advisors LLC | History | No change | 12,055 | 132 | 0.0% | 0.0% | 53 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| WELLS FARGO & COMPANY/MN | History | No change | 11,300 | 124 | 0.0% | 0.0% | 54 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Invesco Ltd. | History | No change | 10,839 | 119 | 0.0% | 0.0% | 55 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| TUDOR INVESTMENT CORP ET AL | History | No change | 10,400 | 114 | 0.0% | 0.0% | 56 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Vanguard Global Advisers, LLC | History | No change | 6,000 | 66 | 0.0% | 0.0% | 57 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| State of Alaska, Department of Revenue | History | New | 1,936 | 61 | 0.0% | — | 58 | +1,936 | New | Q3 2026 | Oct 15, 2026 |
| JPMORGAN CHASE & CO | History | No change | 3,680 | 43 | 0.0% | 0.0% | 59 | 0 | 0.0% | Q2 2026 | Aug 12, 2026 |
| SBI Securities Co., Ltd. | History | Added to | 1,324 | 41 | 0.0% | 0.0% | 60 | +254 | 23.74% | Q3 2026 | Oct 21, 2026 |
| Global Retirement Partners, LLC | History | Added to | 961 | 30 | 0.0% | — | 61 | +896 | 1378.46% | Q3 2026 | Nov 10, 2026 |
| SIGNATUREFD, LLC | History | New | 696 | 22 | 0.0% | — | 62 | +696 | New | Q3 2026 | Oct 23, 2026 |
| JONES FINANCIAL COMPANIES LLLP | History | No change | 1,580 | 18 | 0.0% | 0.0% | 63 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| GROUP ONE TRADING LLC | History | New | 510 | 16 | 0.0% | — | 64 | +510 | New | Q3 2026 | Nov 10, 2026 |
| Carolina Wealth Advisors, LLC | History | New | 416 | 13 | 0.0% | — | 66 | +416 | New | Q3 2026 | Oct 23, 2026 |
| BNP PARIBAS FINANCIAL MARKETS | History | No change | 1,187 | 13 | 0.0% | 0.0% | 65 | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| HARBOUR INVESTMENTS, INC. | History | Added to | 403 | 12 | 0.0% | 0.0% | 67 | +220 | 120.22% | Q3 2026 | Nov 09, 2026 |
| FEDERATED HERMES, INC. | History | No change | 1,158 | 12 | 0.0% | 0.0% | 68 | 0 | 0.0% | Q2 2026 | Aug 12, 2026 |
| FIFTH THIRD BANCORP | History | New | 273 | 8 | 0.0% | — | 70 | +273 | New | Q3 2026 | Nov 05, 2026 |
| ROYAL BANK OF CANADA | History | No change | 765 | 8 | 0.0% | 0.0% | 69 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Tower Research Capital LLC (TRC) | History | No change | 655 | 7 | 0.0% | 0.0% | 71 | 0 | 0.0% | Q2 2026 | Aug 11, 2026 |
| CITIGROUP INC | History | Reduced | 208 | 6 | 0.0% | 0.0% | 72 | -14,218 | -98.56% | Q3 2026 | Nov 04, 2026 |
| OSAIC HOLDINGS, INC. | History | No change | 485 | 5 | 0.0% | 0.0% | 73 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Caitong International Asset Management Co., Ltd | History | New | 121 | 3 | 0.0% | — | 74 | +121 | New | Q3 2026 | Oct 29, 2026 |
| BLUE BELL PRIVATE WEALTH MANAGEMENT, LLC | History | New | 34 | 1 | 0.0% | — | 77 | +34 | New | Q3 2026 | Oct 29, 2026 |
| EFG International AG | History | No change | 100 | 1 | 0.0% | 0.0% | 75 | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| BFC Planning, Inc. | History | No change | 172 | 1 | 0.0% | 0.0% | 76 | 0 | 0.0% | Q2 2026 | Oct 29, 2026 |
| FMR LLC | History | Reduced | 1 | 0 | — | 0.0% | — | -105 | -99.06% | Q3 2026 | Nov 10, 2026 |
| GK Wealth Management LLC | History | New | 13 | 0 | — | — | — | +13 | New | Q3 2026 | Oct 09, 2026 |
| Cassaday & Co Wealth Management LLC | History | New | 7 | 0 | — | — | — | +7 | New | Q3 2026 | Oct 27, 2026 |
| HOLLENCREST CAPITAL MANAGEMENT | History | No change | 10 | 0 | — | — | — | 0 | 0.0% | Q2 2026 | Aug 13, 2026 |
| Continuum Advisory, LLC | History | No change | 34 | 0 | — | — | — | 0 | 0.0% | Q2 2026 | Aug 06, 2026 |
| Quarry LP | History | No change | 17 | 0 | — | — | — | 0 | 0.0% | Q2 2026 | Aug 14, 2026 |
| Farther Finance Advisors, LLC | History | No change | 4 | 0 | — | — | — | 0 | 0.0% | Q3 2026 | Oct 08, 2026 |