MAGNITE, INC. (MGNI) — Institutional Holders, Q2 2026
312 institutional investment managers reported a MGNI position on SEC Form 13F-HR for the quarter ended June 30, 2026, with a combined reported value of $2.7B. Every filer is listed below, ranked by position value, 100 per page; this page shows ranks 1 to 100. Put and call option positions are excluded, and a firm filing several lots or share classes is shown once with its total.
MGNI 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
- FMRAdded · +3,252,007 sh+$61.7M
- CANADA PENSION PLAN INVESTMENT BOARDAdded · +2,949,041 sh+$56.0M
- 325 CAPITALAdded · +1,407,307 sh+$26.7M
- Park West Asset ManagementAdded · +1,401,620 sh+$26.6M
- Qube Research & Technologies LtdAdded · +1,294,932 sh+$24.6M
Biggest sellers
- WELLINGTON MANAGEMENT GROUP LLPTrimmed · -3,146,585 sh-$59.7M
- No Street GPSold out · -1,628,248 sh-$30.9M
- Capital Research Global InvestorsTrimmed · -1,151,130 sh-$21.8M
- Schonfeld Strategic AdvisorsTrimmed · -1,042,846 sh-$19.8M
- BALYASNY ASSET MANAGEMENT L.P.Trimmed · -833,889 sh-$15.8M
MGNI 13F holders ranked 1–100 of 312
| # | Institution | Shares | Value | % of portfolio | QoQShares vs Q1 2026 |
|---|---|---|---|---|---|
| 1 | BlackRock#1 · 12,713,156 sh | 12,713,156 | $241.3M | <0.01% | +9.1% |
| 2 | VANGUARD PORTFOLIO MANAGEMENT#2 · 8,197,286 sh | 8,197,286 | $155.6M | <0.01% | +6.1% |
| 3 | FMR#3 · 7,759,426 sh | 7,759,426 | $147.3M | <0.01% | +72.1% |
| 4 | VANGUARD CAPITAL MANAGEMENT#4 · 6,225,195 sh | 6,225,195 | $118.2M | <0.01% | +0.6% |
| 5 | WELLINGTON MANAGEMENT GROUP LLP#5 · 6,044,492 sh | 6,044,492 | $114.7M | 0.02% | -34.2% |
| 6 | DIMENSIONAL FUND ADVISORS#6 · 5,260,132 sh | 5,260,132 | $99.8M | 0.02% | +32.0% |
| 7 | Boston Partners#7 · 5,013,835 sh | 5,013,835 | $95.9M | 0.09% | +6.2% |
| 8 | AMERICAN CENTURY COMPANIES#8 · 4,622,736 sh | 4,622,736 | $87.7M | 0.04% | -0.1% |
| 9 | Capital Research Global Investors#9 · 3,869,159 sh | 3,869,159 | $73.4M | 0.01% | -22.9% |
| 10 | Nuveen#10 · 3,794,811 sh | 3,794,811 | $72.0M | 0.02% | +5.7% |
| 11 | GEODE CAPITAL MANAGEMENT#11 · 3,789,959 sh | 3,789,959 | $71.9M | <0.01% | +6.6% |
| 12 | Edenbrook Capital#12 · 3,555,615 sh | 3,555,615 | $67.5M | 13.60% | +27.1% |
| 13 | STATE STREET#13 · 3,528,075 sh | 3,528,075 | $67.0M | <0.01% | +11.5% |
| 14 | 325 CAPITAL#14 · 3,412,694 sh | 3,412,694 | $64.8M | 15.44% | +70.2% |
| 15 | Nine Ten Capital Management#15 · 3,261,283 sh | 3,261,283 | $61.9M | 19.26% | -6.3% |
| 16 | Granahan Investment Management#16 · 3,083,211 sh | 3,083,211 | $58.5M | 2.09% | +20.7% |
| 17 | CANADA PENSION PLAN INVESTMENT BOARD#17 · 2,995,093 sh | 2,995,093 | $56.8M | 0.03% | +6403.7% |
| 18 | JANE STREET GROUP#18 · 2,199,191 sh | 2,199,191 | $41.7M | <0.01% | +31.8% |
| 19 | Park West Asset Management#19 · 2,000,000 sh | 2,000,000 | $38.0M | 2.59% | +234.2% |
| 20 | MORGAN STANLEY#20 · 1,991,732 sh | 1,991,732 | $37.8M | <0.01% | +114.9% |
| 21 | Qube Research & Technologies Ltd#21 · 1,955,989 sh | 1,955,989 | $37.1M | 0.03% | +195.9% |
| 22 | Blue Grotto Capital#22 · 1,706,741 sh | 1,706,741 | $32.4M | 2.70% | +28.4% |
| 23 | KENNEDY CAPITAL MANAGEMENT#23 · 1,666,799 sh | 1,666,799 | $31.6M | 0.56% | -4.9% |
| 24 | NORTHERN#24 · 1,553,412 sh | 1,553,412 | $29.5M | <0.01% | +17.5% |
| 25 | ROYCE & ASSOCIATES#25 · 1,473,397 sh | 1,473,397 | $28.0M | 0.23% | +7.9% |
| 26 | GOLDMAN SACHS GROUP#26 · 1,466,640 sh | 1,466,640 | $27.8M | <0.01% | -2.3% |
| 27 | Ophir Asset Management Pty Ltd#27 · 1,450,061 sh | 1,450,061 | $27.5M | 2.26% | -31.5% |
| 28 | VICTORY CAPITAL MANAGEMENT#28 · 1,235,384 sh | 1,235,384 | $23.4M | 0.01% | -2.5% |
| 29 | CHARLES SCHWAB INVESTMENT MANAGEMENT#29 · 1,203,189 sh | 1,203,189 | $22.8M | <0.01% | +1.9% |
| 30 | BANK OF AMERICA#30 · 1,181,832 sh | 1,181,832 | $22.4M | <0.01% | +5.0% |
| 31 | GRIZZLYROCK CAPITAL#31 · 1,164,628 sh | 1,164,628 | $22.1M | 15.46% | -6.0% |
| 32 | Bank of New York Mellon#32 · 1,162,198 sh | 1,162,198 | $22.1M | <0.01% | +2.1% |
| 33 | Maestria Partners#33 · 1,158,430 sh | 1,158,430 | $22.0M | — | -15.0% |
| 34 | Meros Investment Management#34 · 991,335 sh | 991,335 | $18.8M | 5.97% | -0.1% |
| 35 | VANGUARD FIDUCIARY#35 · 989,092 sh | 989,092 | $18.8M | <0.01% | -0.8% |
| 36 | MILLENNIUM MANAGEMENT#36 · 764,819 sh | 764,819 | $14.5M | <0.01% | -38.0% |
| 37 | QVT Financial#37 · 747,437 sh | 747,437 | $14.2M | 0.83% | +64.7% |
| 38 | UBS Group AG#38 · 746,350 sh | 746,350 | $14.2M | <0.01% | +65.7% |
| 39 | OBERWEIS ASSET MANAGEMENT#39 · 735,000 sh | 735,000 | $14.0M | 0.29% | +13.5% |
| 40 | SILVERCREST ASSET MANAGEMENT GROUP#40 · 707,749 sh | 707,749 | $13.4M | 0.09% | +14.9% |
| 41 | PICTON MAHONEY ASSET MANAGEMENT#41 · 691,471 sh | 691,471 | $13.1M | 0.10% | +7.5% |
| 42 | Kopion Asset Management#42 · 674,451 sh | 674,451 | $12.8M | — | -21.2% |
| 43 | First Eagle Investment Management#43 · 670,788 sh | 670,788 | $12.7M | 0.02% | +49.0% |
| 44 | BALYASNY ASSET MANAGEMENT L.P.#44 · 666,554 sh | 666,554 | $12.7M | 0.02% | -55.6% |
| 45 | AMERIPRISE FINANCIAL#45 · 619,573 sh | 619,573 | $11.8M | <0.01% | New |
| 46 | S Squared Technology#46 · 567,862 sh | 567,862 | $10.8M | 3.34% | +41.0% |
| 47 | Schonfeld Strategic Advisors#47 · 562,195 sh | 562,195 | $10.7M | 0.04% | -65.0% |
| 48 | NOMURA ASSET MANAGEMENT LTD#48 · 553,900 sh | 553,900 | $10.5M | 0.02% | -6.7% |
| 49 | BANK OF MONTREAL#49 · 533,757 sh | 533,757 | $10.1M | <0.01% | New |
| 50 | KING LUTHER CAPITAL MANAGEMENT#50 · 503,581 sh | 503,581 | $9.6M | 0.04% | -5.2% |
| 51 | PRINCIPAL FINANCIAL GROUP#51 · 497,522 sh | 497,522 | $9.4M | <0.01% | +11.6% |
| 52 | EVR Research#52 · 480,000 sh | 480,000 | $9.1M | 4.50% | New |
| 53 | CITADEL ADVISORS#53 · 472,865 sh | 472,865 | $9.0M | <0.01% | -55.1% |
| 54 | SUSQUEHANNA INTERNATIONAL GROUP, LLP#54 · 461,849 sh | 461,849 | $8.8M | <0.01% | +50.0% |
| 55 | Manatuck Hill Partners#55 · 450,000 sh | 450,000 | $8.5M | 2.83% | +45.2% |
| 56 | Jump Financial#56 · 428,036 sh | 428,036 | $8.1M | 0.07% | New |
| 57 | JPMORGAN CHASE#57 · 407,025 sh | 407,025 | $7.9M | <0.01% | -16.4% |
| 58 | NORDEA INVESTMENT MANAGEMENT AB#58 · 386,327 sh | 386,327 | $7.4M | <0.01% | -8.2% |
| 59 | COMMONWEALTH EQUITY SERVICES#59 · 368,199 sh | 368,199 | $7.0M | <0.01% | +2.4% |
| 60 | UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AME#60 · 364,638 sh | 364,638 | $6.9M | <0.01% | +12.9% |
| 61 | MARSHALL WACE, LLP#61 · 341,864 sh | 341,864 | $6.5M | <0.01% | +705.0% |
| 62 | Trexquant Investment#62 · 333,429 sh | 333,429 | $6.3M | 0.04% | New |
| 63 | Alyeska Investment Group, L.P.#63 · 326,839 sh | 326,839 | $6.2M | 0.02% | New |
| 64 | 1492 Capital Management#64 · 317,750 sh | 317,750 | $6.0M | 1.78% | -6.7% |
| 65 | HARBOR CAPITAL ADVISORS#65 · 312,371 sh | 312,371 | $5.9M | — | -4.0% |
| 66 | RAYMOND JAMES FINANCIAL#66 · 309,931 sh | 309,931 | $5.9M | <0.01% | +6.2% |
| 67 | Swiss National Bank#67 · 289,700 sh | 289,700 | $5.5M | <0.01% | +1.9% |
| 68 | Lisanti Capital Growth#68 · 289,030 sh | 289,030 | $5.5M | 1.21% | -6.6% |
| 69 | RICE HALL JAMES & ASSOCIATES#69 · 283,919 sh | 283,919 | $5.4M | 0.26% | +47.3% |
| 70 | ExodusPoint Capital Management#70 · 271,869 sh | 271,869 | $5.2M | 0.03% | +82.2% |
| 71 | Norwood Investment Partners#71 · 235,000 sh | 235,000 | $4.5M | 6.16% | -17.5% |
| 72 | BARCLAYS PLC#72 · 233,693 sh | 233,693 | $4.4M | <0.01% | +29.4% |
| 73 | Squarepoint Ops#73 · 230,234 sh | 230,234 | $4.4M | <0.01% | -23.5% |
| 74 | Senvest Management#74 · 224,100 sh | 224,100 | $4.3M | 0.12% | 0.0% |
| 75 | Invesco Ltd.#75 · 222,213 sh | 222,213 | $4.2M | <0.01% | -15.0% |
| 76 | Hilton Capital Management#76 · 219,406 sh | 219,406 | $4.2M | 0.28% | +5.4% |
| 77 | Pillsbury Lake Capital#77 · 217,753 sh | 217,753 | $4.1M | 1.13% | New |
| 78 | Occam Crest Management#78 · 195,000 sh | 195,000 | $3.8M | 2.00% | New |
| 79 | Cerity Partners#79 · 200,984 sh | 200,984 | $3.8M | <0.01% | +98.6% |
| 80 | PRICE T ROWE ASSOCIATES#80 · 199,445 sh | 199,445 | $3.8M | <0.01% | +20.6% |
| 81 | VOYA INVESTMENT MANAGEMENT#81 · 196,662 sh | 196,662 | $3.7M | <0.01% | -6.6% |
| 82 | RHUMBLINE ADVISERS#82 · 195,811 sh | 195,811 | $3.7M | <0.01% | +8.8% |
| 83 | GREAT LAKES ADVISORS#83 · 176,615 sh | 176,615 | $3.4M | 0.03% | New |
| 84 | AQR CAPITAL MANAGEMENT#84 · 176,599 sh | 176,599 | $3.4M | <0.01% | +45.7% |
| 85 | STATE OF WISCONSIN INVESTMENT BOARD#85 · 172,277 sh | 172,277 | $3.3M | <0.01% | -7.1% |
| 86 | DEAN INVESTMENT ASSOCIATES#86 · 167,927 sh | 167,927 | $3.2M | 0.42% | New |
| 87 | Legato Capital Management#87 · 166,918 sh | 166,918 | $3.2M | 0.26% | +96.9% |
| 88 | Toroso Investments#88 · 165,838 sh | 165,838 | $3.1M | <0.01% | +24.0% |
| 89 | SEI INVESTMENTS#89 · 165,553 sh | 165,553 | $3.1M | <0.01% | -52.8% |
| 90 | DEUTSCHE BANK AG\#90 · 165,040 sh | 165,040 | $3.1M | <0.01% | +18.2% |
| 91 | LPL Financial#91 · 163,837 sh | 163,837 | $3.1M | <0.01% | +5.4% |
| 92 | Quantinno Capital Management#92 · 161,782 sh | 161,782 | $3.1M | <0.01% | +26.3% |
| 93 | P.A.W. CAPITAL#93 · 160,000 sh | 160,000 | $3.0M | 2.29% | -5.9% |
| 94 | CLOUGH CAPITAL PARTNERS L P#94 · 159,586 sh | 159,586 | $3.0M | 0.25% | New |
| 95 | Concentric Capital Strategies#95 · 146,698 sh | 146,698 | $2.8M | 0.15% | New |
| 96 | Caption Management#96 · 145,590 sh | 145,590 | $2.8M | 0.01% | -64.1% |
| 97 | VANGUARD ASSET MANAGEMENT, Ltd#97 · 140,438 sh | 140,438 | $2.7M | <0.01% | +11.1% |
| 98 | ALGERT GLOBAL#98 · 137,505 sh | 137,505 | $2.6M | 0.03% | -48.9% |
| 99 | WELLS FARGO & COMPANY#99 · 137,396 sh | 137,396 | $2.6M | <0.01% | +107.9% |
| 100 | FRANKLIN RESOURCES#100 · 122,336 sh | 122,336 | $2.3M | <0.01% | +11.6% |
Funds that sold out of MGNI in Q2 2026 (36)
Held MGNI 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 |
|---|---|---|
| No Street GP1,628,248 sh | 1,628,248 | $19.3M |
| Capital World Investors456,672 sh | 456,672 | $5.4M |
| WEDGE CAPITAL MANAGEMENT L L P189,767 sh | 189,767 | $2.3M |
| Walleye Trading179,394 sh | 179,394 | $2.1M |
| Brevan Howard Capital Management133,245 sh | 133,245 | $1.6M |
| TWINBEECH CAPITAL132,379 sh | 132,379 | $1.6M |
| Holocene Advisors101,973 sh | 101,973 | $1.2M |
| TEACHERS RETIREMENT SYSTEM OF THE STATE OF KENTUCKY76,813 sh | 76,813 | $913.0K |
| TUDOR INVESTMENT ET AL73,645 sh | 73,645 | $874.9K |
| JENNISON ASSOCIATES57,849 sh | 57,849 | $687.2K |
| NATIXIS42,100 sh | 42,100 | $500.1K |
| GROUP ONE TRADING, L.P.24,999 sh | 24,999 | $297.0K |
| Entropy Technologies24,761 sh | 24,761 | $294.2K |
| Dynamic Technology Lab Private Ltd22,162 sh | 22,162 | $263.3K |
| Virtu Financial20,044 sh | 20,044 | $238.0K |
| STRS OHIO18,500 sh | 18,500 | $219.8K |
| Centiva Capital17,000 sh | 17,000 | $202.0K |
| Cambridge Investment Research Advisors15,022 sh | 15,022 | $178.0K |
| GSA CAPITAL PARTNERS LLP13,347 sh | 13,347 | $159.0K |
| Bayforest Capital Ltd13,225 sh | 13,225 | $157.1K |
| Gotham Asset Management12,885 sh | 12,885 | $153.1K |
| OP Asset Management Ltd12,621 sh | 12,621 | $149.9K |
| Sciencast Management11,704 sh | 11,704 | $139.0K |
| SIMPLEX TRADING11,316 sh | 11,316 | $134.4K |
| RITHOLTZ WEALTH MANAGEMENT10,334 sh | 10,334 | $122.8K |
| Vanguard Personalized Indexing Management10,311 sh | 10,311 | $122.5K |
| Optiver Holding B.V.5,579 sh | 5,579 | $66.3K |
| MCF Advisors1,500 sh | 1,500 | $17.8K |
| MAI Capital Management1,145 sh | 1,145 | $13.6K |
| Essential Partners696 sh | 696 | $8.3K |
| Root Financial Partners228 sh | 228 | $2.7K |
| Western Wealth Management103 sh | 103 | $1.2K |
| IFP Advisors49 sh | 49 | $582.00 |
| TWIN PEAKS WEALTH ADVISORS29 sh | 29 | $345.00 |
| Wealth Preservation Advisors8 sh | 8 | $95.00 |
| Kilter Group1 sh | 1 | $12.00 |
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.