QUANTUM CORP /DE/ (QMCO) — Institutional Holders, Q2 2026
61 institutional investment managers reported a QMCO position on SEC Form 13F-HR for the quarter ended June 30, 2026, with a combined reported value of $158.1M. Every filer is listed below, ranked by position value. Put and call option positions are excluded, and a firm filing several lots or share classes is shown once with its total.
QMCO in Q2 2026: what funds did
Funds that filed a 13F for both Q1 2026 and Q2 2026, by what they did with the common stock. Share counts are adjusted for any split between the two quarters; dollar figures are the change in shares at this quarter’s price.
Biggest buyers
- Alyeska Investment Group, L.P.New · +2,653,928 sh+$29.2M
- Two Seas CapitalNew · +2,488,535 sh+$27.4M
- OAKTREE CAPITAL MANAGEMENTNew · +2,011,678 sh+$22.1M
- Neuberger Berman GroupNew · +1,163,315 sh+$12.8M
- ASHFORD CAPITAL MANAGEMENTNew · +1,039,200 sh+$11.4M
Biggest sellers
- UBS Group AGTrimmed · -52,962 sh-$582.6K
- Cygnus Capital AdvisorsTrimmed · -49,763 sh-$547.4K
- LPL FinancialSold out · -24,598 sh-$270.6K
- R Squared LtdSold out · -12,245 sh-$134.7K
- BARCLAYS PLCTrimmed · -11,988 sh-$131.9K
QMCO 13F holders ranked 1–61 of 61
| # | Institution | Shares | Value | % of portfolio | QoQShares vs Q1 2026 |
|---|---|---|---|---|---|
| 1 | Alyeska Investment Group, L.P.#1 · 2,653,928 sh | 2,653,928 | $29.2M | 0.08% | New |
| 2 | Two Seas Capital#2 · 2,488,535 sh | 2,488,535 | $27.4M | — | New |
| 3 | OAKTREE CAPITAL MANAGEMENT#3 · 2,011,678 sh | 2,011,678 | $22.1M | 0.31% | New |
| 4 | Neuberger Berman Group#4 · 1,163,315 sh | 1,163,315 | $12.8M | <0.01% | New |
| 5 | Portolan Capital Management#5 · 1,020,120 sh | 1,020,120 | $11.2M | 0.42% | New |
| 6 | ASHFORD CAPITAL MANAGEMENT#6 · 1,039,200 sh | 1,039,200 | $10.6M | 1.13% | New |
| 7 | MARSHALL WACE, LLP#7 · 713,075 sh | 713,075 | $7.8M | <0.01% | +1800.1% |
| 8 | VANGUARD CAPITAL MANAGEMENT#8 · 605,541 sh | 605,541 | $6.7M | <0.01% | +12.3% |
| 9 | Manatuck Hill Partners#9 · 350,000 sh | 350,000 | $3.9M | 1.28% | New |
| 10 | BlackRock#10 · 273,030 sh | 273,030 | $3.0M | 0.00% | +25.5% |
| 11 | Cinctive Capital Management#11 · 182,769 sh | 182,769 | $2.0M | 0.07% | New |
| 12 | BANK OF AMERICA#12 · 170,130 sh | 170,130 | $1.9M | <0.01% | +730.5% |
| 13 | GEODE CAPITAL MANAGEMENT#13 · 164,600 sh | 164,600 | $1.8M | <0.01% | +3.4% |
| 14 | RENAISSANCE TECHNOLOGIES#14 · 154,516 sh | 154,516 | $1.7M | <0.01% | New |
| 15 | SONA ASSET MANAGEMENT (US)#15 · 150,000 sh | 150,000 | $1.6M | 0.03% | +114.0% |
| 16 | Walleye Capital#16 · 120,044 sh | 120,044 | $1.3M | <0.01% | New |
| 17 | RAYMOND JAMES FINANCIAL#17 · 103,836 sh | 103,836 | $1.1M | <0.01% | New |
| 18 | Centiva Capital#18 · 100,000 sh | 100,000 | $1.1M | <0.01% | New |
| 19 | VANGUARD FIDUCIARY#19 · 89,125 sh | 89,125 | $980.4K | <0.01% | +11.0% |
| 20 | KKM Financial#20 · 90,274 sh | 90,274 | $960.5K | 0.13% | New |
| 21 | Qube Research & Technologies Ltd#21 · 80,977 sh | 80,977 | $890.7K | <0.01% | New |
| 22 | STATE STREET#22 · 75,914 sh | 75,914 | $835.1K | 0.00% | +4.3% |
| 23 | Cygnus Capital Advisors#23 · 74,323 sh | 74,323 | $818.0K | 0.56% | -40.1% |
| 24 | SUSQUEHANNA INTERNATIONAL GROUP, LLP#24 · 69,775 sh | 69,775 | $767.5K | <0.01% | New |
| 25 | Man Group plc#25 · 68,593 sh | 68,593 | $754.5K | <0.01% | New |
| 26 | Informed Momentum#26 · 64,857 sh | 64,857 | $713.4K | 0.06% | New |
| 27 | UBS Group AG#27 · 46,106 sh | 46,106 | $507.2K | <0.01% | -53.5% |
| 28 | SEI INVESTMENTS#28 · 38,739 sh | 38,739 | $426.1K | <0.01% | New |
| 29 | SUSQUEHANNA FUNDAMENTAL INVESTMENTS#29 · 34,601 sh | 34,601 | $380.6K | <0.01% | New |
| 30 | Squarepoint Ops#30 · 33,817 sh | 33,817 | $372.0K | <0.01% | New |
| 31 | NORTHERN#31 · 33,220 sh | 33,220 | $365.4K | 0.00% | +15.5% |
| 32 | PRICE T ROWE ASSOCIATES#32 · 25,069 sh | 25,069 | $276.0K | 0.00% | +15.0% |
| 33 | MILLENNIUM MANAGEMENT#33 · 21,755 sh | 21,755 | $239.3K | <0.01% | New |
| 34 | GOLDMAN SACHS GROUP#34 · 19,153 sh | 19,153 | $210.7K | 0.00% | New |
| 35 | BRIDGEWAY CAPITAL MANAGEMENT#35 · 16,240 sh | 16,240 | $178.6K | <0.01% | 0.0% |
| 36 | MORGAN STANLEY#36 · 15,492 sh | 15,492 | $170.4K | 0.00% | +2.1% |
| 37 | CITIGROUP#37 · 14,426 sh | 14,426 | $158.7K | <0.01% | New |
| 38 | Kovack Advisors#38 · 13,430 sh | 13,430 | $146.8K | <0.01% | +7.6% |
| 39 | Schonfeld Strategic Advisors#39 · 12,055 sh | 12,055 | $132.6K | <0.01% | New |
| 40 | WELLS FARGO & COMPANY#40 · 11,300 sh | 11,300 | $124.3K | 0.00% | +173.9% |
| 41 | FLAGSHIP HARBOR ADVISORS#41 · 11,004 sh | 11,004 | $121.0K | — | -36.0% |
| 42 | Invesco Ltd.#42 · 10,839 sh | 10,839 | $119.2K | 0.00% | New |
| 43 | Vanguard Global Advisers#43 · 6,000 sh | 6,000 | $66.0K | 0.00% | 0.0% |
| 44 | JPMORGAN CHASE#44 · 3,680 sh | 3,680 | $43.6K | 0.00% | New |
| 45 | JONES FINANCIAL COMPANIES LLLP#45 · 1,580 sh | 1,580 | $18.4K | 0.00% | +7.7% |
| 46 | BNP PARIBAS FINANCIAL MARKETS#46 · 1,187 sh | 1,187 | $13.1K | 0.00% | +354.8% |
| 47 | FEDERATED HERMES#47 · 1,158 sh | 1,158 | $12.7K | 0.00% | +38.7% |
| 48 | SBI Securities , Ltd.#48 · 1,070 sh | 1,070 | $11.8K | — | -46.6% |
| 49 | ROYAL BANK OF CANADA#49 · 765 sh | 765 | $8.0K | 0.00% | +497.7% |
| 50 | Tower Research Capital (TRC)#50 · 655 sh | 655 | $7.2K | <0.01% | New |
| 51 | OSAIC#51 · 485 sh | 485 | $5.3K | 0.00% | -49.7% |
| 52 | BARCLAYS PLC#52 · 455 sh | 455 | $5.0K | 0.00% | -96.3% |
| 53 | HARBOUR INVESTMENTS#53 · 183 sh | 183 | $2.0K | 0.00% | New |
| 54 | FMR#54 · 106 sh | 106 | $1.2K | 0.00% | New |
| 55 | EFG International AG#55 · 100 sh | 100 | $1.1K | 0.00% | 0.0% |
| 56 | Global Retirement Partners#56 · 65 sh | 65 | $715.00 | 0.00% | — |
| 57 | Continuum Advisory#57 · 34 sh | 34 | $374.00 | 0.00% | New |
| 58 | Quarry#58 · 17 sh | 17 | $187.00 | 0.00% | New |
| 59 | HOLLENCREST SECURITIES#59 · 10 sh | 10 | $110.00 | 0.00% | -99.5% |
| 60 | Farther Finance Advisors#60 · 4 sh | 4 | $44.00 | — | 0.0% |
| 61 | NewEdge Advisors#61 · 0 sh | 0 | $0.00 | 0.00% | New |
Funds that sold out of QMCO in Q2 2026 (8)
Held QMCO at the end of Q1 2026 and filed a Q2 2026 13F without it. Not in the list above, because they no longer hold it. Largest prior position first.
| Institution | Shares sold | Value in Q1 2026 |
|---|---|---|
| LPL Financial24,598 sh | 24,598 | $116.8K |
| R Squared Ltd12,245 sh | 12,245 | $58.2K |
| XTX Topco Ltd11,321 sh | 11,321 | $53.8K |
| NATIONAL BANK OF CANADA100 sh | 100 | $475.00 |
| Rialto Wealth Management87 sh | 87 | $414.00 |
| Lavaca Capital39 sh | 39 | $185.00 |
| Federation des caisses Desjardins du Quebec25 sh | 25 | $119.00 |
| Activest Wealth Management1 sh | 1 | $4.00 |
Source: Form 13F-HR filings on SEC EDGAR, Q2 2026. Values are as reported by each manager at quarter end. “% of portfolio” is the position’s share of the manager’s total reported 13F value for the same quarter. “New” means the manager filed a 13F for Q1 2026 without this position; a dash means no comparison is available. Where a manager’s own filing is internally inconsistent its value is withheld and it is listed last. 13F data shows reported holdings, not recommendations.