MAGNITE INC MGNI
COM · Common Stock · CUSIP 55955D100 · ISIN US55955D1000
American advertising technology and real-time bidding, serving as ad exchange
- SectorTechnology
- IndustryServices-Computer Programming, Data Processing, Etc.
- HeadquartersNew York, NY
- Founded2007
- Websitemagnite.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($1.5m this quarter). Holder counts are more reliable. Shares outstanding: 143.6m as of 2025-10-31, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $16.23. Options: 22 managers hold calls ($98.0m notional), 14 hold puts ($69.7m).
Trends to Q4 2025
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 218 |
| Q4 2022 | 230 |
| Q1 2023 | 223 |
| Q2 2023 | 225 |
| Q3 2023 | 215 |
| Q4 2023 | 217 |
| Q1 2024 | 232 |
| Q2 2024 | 269 |
| Q3 2024 | 280 |
| Q4 2024 | 286 |
| Q1 2025 | 295 |
| Q2 2025 | 288 |
| Q3 2025 | 317 |
| Q4 2025 | 304 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q1 2024 | 112 | 93 |
| Q2 2024 | 171 | 95 |
| Q3 2024 | 146 | 108 |
| Q4 2024 | 137 | 133 |
| Q1 2025 | 155 | 136 |
| Q2 2025 | 150 | 156 |
| Q3 2025 | 152 | 164 |
| Q4 2025 | 167 | 149 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q1 2025 | $41.6m | $50.1m | 1.20 |
| Q2 2025 | $125.7m | $106.9m | 0.85 |
| Q3 2025 | $136.4m | $99.8m | 0.73 |
| Q4 2025 | $98.0m | $69.7m | 0.71 |
Biggest buyers
| Capital Research Global Investors | Added | +5.9m |
| WELLINGTON MANAGEMENT GROUP LLP | Added | +3.5m |
| Ophir Asset Management Pty Ltd | New | +2.4m |
| No Street GP LP | New | +1.5m |
| 325 CAPITAL LLC | Added | +1.4m |
| Balyasny Asset Management L.P. | New | +873.2k |
| Schonfeld Strategic Advisors LLC | New | +779.7k |
| AMERICAN CENTURY COMPANIES INC | Added | +692.9k |
| Edenbrook Capital, LLC | Added | +677.7k |
| ALGERT GLOBAL LLC | Added | +462.6k |
Biggest sellers
| FMR LLC | Reduced | -10.4m |
| JPMORGAN CHASE & CO | Reduced | -1.9m |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -1.8m |
| Driehaus Capital Management LLC | Sold out | -1.5m |
| T. Rowe Price Investment Management, Inc. | Sold out | -890.9k |
| Granahan Investment Management, LLC | Reduced | -757.2k |
| NOMURA ASSET MANAGEMENT CO LTD | Reduced | -717.1k |
| JANE STREET GROUP, LLC | Reduced | -710.4k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -652.6k |
| GOLDMAN SACHS GROUP INC | Reduced | -624.4k |
Biggest calls
| Edenbrook Capital, LLC | New | $24.3m1.5m shares |
| Caption Management, LLC | Reduced | $19.2m1.2m shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $12.3m760.5k shares |
| Walleye Trading LLC | Added | $7.2m441.3k shares |
| CITADEL ADVISORS LLC | Added | $7.1m438.2k shares |
| IMC-Chicago, LLC | Reduced | $6.1m376.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $4.5m277.1k shares |
| GROUP ONE TRADING LLC | Added | $3.6m224.1k shares |
| JANE STREET GROUP, LLC | Reduced | $3.6m220.5k shares |
| TUDOR INVESTMENT CORP ET AL | Added | $2.9m177.1k shares |
Biggest puts
| Squarepoint Ops LLC | Reduced | $27.8m1.7m shares |
| CITADEL ADVISORS LLC | Added | $12.3m760.2k shares |
| PEAK6 LLC | Reduced | $8.3m513.6k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $4.3m262.7k shares |
| SIMPLEX TRADING, LLC | Reduced | $2.7m169.1k shares |
| Walleye Trading LLC | Added | $2.7m165.6k shares |
| Caption Management, LLC | Reduced | $2.6m162.5k shares |
| JANE STREET GROUP, LLC | Added | $2.1m130.5k shares |
| IMC-Chicago, LLC | Added | $2.0m125.2k shares |
| GROUP ONE TRADING LLC | Added | $1.7m106.6k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| VANGUARD PORTFOLIO MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 5.4% |
| FMR LLC 13G · institution +2.3 pts · filed 2026-08-06 | 5.4% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 | 5.0% |
Fell to 5% or below in the last year: WELLINGTON MANAGEMENT GROUP LLP (4.2%, 2026-08-13), Capital Research Global Investors (3.5%, 2026-05-14), VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD PORTFOLIO MANAGEMENT LLC)
Insider purchases and sales in Q4 2025
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q1 2024 | 0 | — | 2 | $1.0m | $195.2k |
| Q2 2024 | 0 | — | 8 | $3.1m | $2.1m |
| Q3 2024 | 0 | — | 6 | $3.9m | $2.4m |
| Q4 2024 | 0 | — | 9 | $7.0m | $6.8m |
| Q1 2025 | 0 | — | 8 | $5.8m | $5.7m |
| Q2 2025 | 0 | — | 12 | $17.7m | $17.0m |
| Q3 2025 | 0 | — | 11 | $11.2m | $6.3m |
| Q4 2025 | 0 | — | 4 | $795.8k | $618.0k |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-12-17 | Soroca Adam Lee CHIEF PRODUCT OFFICER | Sold plan | $283.2k16.7k shares |
| 2025-11-24 | Buckley Sean Patrick President, Revenue | Sold plan | $32.1k2.2k shares |
| 2025-11-21 | Spillane Robert F Director | Sold | $177.8k12.5k shares |
| 2025-11-18 | Soroca Adam Lee CHIEF PRODUCT OFFICER | Sold plan | $143.6k10.9k shares |
| 2025-11-18 | Buckley Sean Patrick President, Revenue | Sold plan | $59.1k4.4k shares |
| 2025-10-24 | Caine Paul Director | Sold plan | $100.0k5.0k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q4 2025
| Manager | Shares | Change |
|---|---|---|
| VANGUARD GROUP INC 0.00% of their portfolio | 14.8m $240.2m | Added +148.2k |
| Capital Research Global Investors 0.04% of their portfolio | 12.9m $209.7m | Added +5.9m |
| BlackRock, Inc. 0.00% of their portfolio | 11.6m $188.2m | Added +180.1k |
| WELLINGTON MANAGEMENT GROUP LLP 0.02% of their portfolio | 8.6m $140.1m | Added +3.5m |
| FMR LLC 0.01% of their portfolio | 6.7m $108.8m | Reduced -10.4m |
| AMERICAN CENTURY COMPANIES INC 0.04% of their portfolio | 5.3m $85.8m | Added +692.9k |
| Boston Partners 0.07% of their portfolio | 4.1m $66.6m | Reduced -340.1k |
| DIMENSIONAL FUND ADVISORS LP 0.01% of their portfolio | 3.6m $58.7m | Added +48.6k |
| Nuveen, LLC 0.02% of their portfolio | 3.5m $57.3m | Added +439.1k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 3.4m $55.7m | Added +35.0k |
| STATE STREET CORP 0.00% of their portfolio | 3.1m $51.0m | Added +15.2k |
| Granahan Investment Management, LLC 2.17% of their portfolio | 3.1m $50.6m | Reduced -757.2k |
| Nine Ten Capital Management LLC 15.43% of their portfolio | 3.0m $48.7m | Added +145.0k |
| Edenbrook Capital, LLC 19.10% of their portfolio | 2.8m $45.2m | Added +677.7k |
| Ophir Asset Management Pty Ltd 4.34% of their portfolio | 2.4m $38.7m | New |
| 325 CAPITAL LLC 11.40% of their portfolio | 2.0m $32.5m | Added +1.4m |
| MORGAN STANLEY 0.00% of their portfolio | 1.9m $30.2m | Reduced -183.7k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 1.8m $28.6m | Reduced -624.4k |
| Blue Grotto Capital, LLC 2.72% of their portfolio | 1.6m $26.4m | Added +80.0k |
| No Street GP LP 1.61% of their portfolio | 1.5m $23.9m | New |
| KENNEDY CAPITAL MANAGEMENT LLC 0.49% of their portfolio | 1.4m $23.3m | Added +222.4k |
| Maestria Partners LLC 6.48% of their portfolio | 1.4m $22.1m | Added +222.3k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 1.3m $20.6m | Reduced -93.0k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 1.2m $19.3m | Reduced -30.3k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 1.2m $19.2m | Reduced -78.6k |
| ROYCE & ASSOCIATES LP 0.19% of their portfolio | 1.2m $18.9m | Added +190.3k |
| Stephens Investment Management Group LLC 0.24% of their portfolio | 1.1m $18.3m | Added +164.0k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.16% of their portfolio | 944.7k $15.3m | Reduced -148.5k |
| Balyasny Asset Management L.P. 0.03% of their portfolio | 873.2k $14.2m | New |
| Meros Investment Management, LP 5.31% of their portfolio | 825.6k $13.4m | Added +211.8k |
| J. Goldman & Co LP 0.49% of their portfolio | 782.8k $12.7m | Reduced -245.9k |
| Schonfeld Strategic Advisors LLC 0.06% of their portfolio | 779.7k $12.7m | New |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 711.5k $11.5m | Reduced -1.8m |
| Penn Capital Management Company, LLC 0.90% of their portfolio | 694.8k $11.3m | Reduced -19.2k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.08% of their portfolio | 685.3k $11.1m | Added +160.4k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 652.0k $10.6m | Reduced -144.3k |
| OBERWEIS ASSET MANAGEMENT INC/ 0.38% of their portfolio | 635.8k $10.3m | Added +121.8k |
| NOMURA ASSET MANAGEMENT CO LTD 0.03% of their portfolio | 622.7k $10.1m | Reduced -717.1k |
| Kopion Asset Management, LLC 7.13% of their portfolio | 614.5k $10.0m | Added +367.9k |
| Apis Capital Advisors, LLC 1.71% of their portfolio | 604.0k $9.8m | Reduced -235.4k |
| Pillsbury Lake Capital LLC 3.86% of their portfolio | 583.6k $9.5m | First filing |
| GRIZZLYROCK CAPITAL, LLC 6.95% of their portfolio | 571.9k $9.3m | Added +181.0k |
| CITADEL ADVISORS LLC 0.01% of their portfolio | 544.3k $8.8m | Added +374.8k |
| KING LUTHER CAPITAL MANAGEMENT CORP 0.03% of their portfolio | 515.6k $8.4m | Added +65.7k |
| ALGERT GLOBAL LLC 0.13% of their portfolio | 509.9k $8.3m | Added +462.6k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 506.4k $8.2m | Reduced -1.9m |
| NEW YORK STATE COMMON RETIREMENT FUND 0.01% of their portfolio | 474.5k $7.7m | Unchanged |
| Russell Investments Group, Ltd. 0.01% of their portfolio | 451.0k $7.3m | Added +141.4k |
| NORDEA INVESTMENT MANAGEMENT AB 0.01% of their portfolio | 445.0k $7.3m | Reduced -2.3k |
| UBS Group AG 0.00% of their portfolio | 404.0k $6.6m | Reduced -21.3k |
| S SQUARED TECHNOLOGY, LLC 2.53% of their portfolio | 402.9k $6.5m | Added +135.0k |
| PICTON MAHONEY ASSET MANAGEMENT 0.07% of their portfolio | 388.1k $6.3m | Added +799 |
| JANE STREET GROUP, LLC 0.01% of their portfolio | 380.3k $6.2m | Reduced -710.4k |
| BARCLAYS PLC 0.00% of their portfolio | 366.4k $5.9m | Added +155.7k |
| TWO SIGMA INVESTMENTS, LP 0.01% of their portfolio | 363.4k $5.9m | Added +63.0k |
| Manatuck Hill Partners, LLC 1.99% of their portfolio | 350.0k $5.7m | Added +709 |
| 1492 Capital Management LLC 2.12% of their portfolio | 341.4k $5.5m | Added +4.7k |
| Norwood Investment Partners, LP 6.03% of their portfolio | 330.0k $5.4m | Reduced -100.0k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 328.3k $5.3m | Added +7.1k |
| Man Group plc 0.01% of their portfolio | 311.5k $5.1m | New |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.01% of their portfolio | 307.6k $5.0m | Reduced -305.4k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 297.7k $4.8m | Reduced -12.9k |
| First Eagle Investment Management, LLC 0.01% of their portfolio | 296.4k $4.8m | Reduced -279.0k |
| Swiss National Bank 0.00% of their portfolio | 280.7k $4.6m | Added +8.1k |
| BANK OF MONTREAL /CAN/ 0.00% of their portfolio | 276.3k $4.5m | Added +34.9k |
| SIMPLEX TRADING, LLC 0.12% of their portfolio | 263.4k $4.3m | Added +146.3k |
| Dana Investment Advisors, Inc. 0.12% of their portfolio | 254.9k $4.1m | Reduced -154.2k |
| COMMONWEALTH EQUITY SERVICES, LLC 0.01% of their portfolio | 254.3k $4.1m | Added +42.0k |
| Invesco Ltd. 0.00% of their portfolio | 243.6k $4.0m | Reduced -15.2k |
| PRINCIPAL FINANCIAL GROUP INC 0.00% of their portfolio | 237.2k $3.9m | Added +74.8k |
| Senvest Management, LLC 0.11% of their portfolio | 224.1k $3.6m | New |
| VOYA INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 220.4k $3.6m | Added +32.3k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.01% of their portfolio | 219.6k $3.6m | Added +12.7k |
| HARBOR CAPITAL ADVISORS, INC. 0.27% of their portfolio | 214.3k $3.5m | Added +42.1k |
| SEI INVESTMENTS CO 0.00% of their portfolio | 211.5k $3.4m | Added +136.6k |
| Qube Research & Technologies Ltd 0.00% of their portfolio | 202.9k $3.3m | Reduced -6.0k |
| AYAL Capital Advisors Ltd 1.78% of their portfolio | 200.0k $3.2m | Added +1.0k |
| FIRST TRUST ADVISORS LP 0.00% of their portfolio | 199.9k $3.2m | Reduced -105.0k |
| RICE HALL JAMES & ASSOCIATES, LLC 0.18% of their portfolio | 198.8k $3.2m | Added +65.6k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 193.6k $3.1m | Added +55.9k |
| WEDGE CAPITAL MANAGEMENT L L P/NC 0.06% of their portfolio | 189.9k $3.1m | Added +59.1k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 183.9k $3.0m | Reduced -33.4k |
| Hilton Capital Management, LLC 0.22% of their portfolio | 180.5k $2.9m | Added +39.4k |
| FEDERATED HERMES, INC. 0.00% of their portfolio | 172.9k $2.8m | Added +149.8k |
| CenterBook Partners LP 0.14% of their portfolio | 172.5k $2.8m | Added +99.8k |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 164.0k $2.7m | Reduced -6.2k |
| PRELUDE CAPITAL MANAGEMENT, LLC 0.18% of their portfolio | 152.2k $2.5m | Added +38.6k |
| VICTORY CAPITAL MANAGEMENT INC 0.00% of their portfolio | 151.1k $2.5m | Added +104.8k |
| Legal & General Group Plc 0.00% of their portfolio | 148.8k $2.4m | Reduced -11.6k |
| Bridgewater Associates, LP 0.01% of their portfolio | 145.2k $2.4m | Reduced -484 |
| P.A.W. CAPITAL CORP 5.16% of their portfolio | 140.0k $2.3m | Added +40.0k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 136.5k $2.2m | Added +3.9k |
| IMC-Chicago, LLC 0.04% of their portfolio | 133.1k $2.2m | New |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.00% of their portfolio | 129.8k $2.1m | Reduced -283.4k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 128.5k $2.1m | Reduced -1.2k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 125.3k $2.0m | Reduced -19.3k |
| Tidal Investments LLC 0.01% of their portfolio | 123.9k $2.0m | Added +24.8k |
| PERKINS CAPITAL MANAGEMENT INC 1.57% of their portfolio | 121.8k $2.0m | Reduced -9.5k |
| BOOTHBAY FUND MANAGEMENT, LLC 0.05% of their portfolio | 117.8k $1.9m | Added +59.0k |
| LPL Financial LLC 0.00% of their portfolio | 116.5k $1.9m | Added +6.6k |