Who owns Magnite, Inc.?
Institutional ownership of MGNI from SEC Form 13F filings across 203 reporting managers. All positions are from one synchronized reporting period — 2026-06-30 books, filed up to 45 days after quarter end — so every row is comparable.
203
13F holders
$1.71B
value, 2026 filers
63.1%
of shares outstanding (90.4M sh)
33
new positions (2026 filers)
Top institutional holders
ordered by shares owned · positions as of 2026-06-30· % of fund = share of the manager's own book · % of co. = share of MGNI's shares outstanding
| # | Manager | Shares | Value | % of fund | % of co. | Δ shares QoQ |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 12.7M | $241.3M | 0.0% | 8.9% | +9.1% |
| 2 | VANGUARD PORTFOLIO MANAGEMENT LLC | 8.2M | $155.6M | 0.0% | 5.7% | +6.1% |
| 3 | FMR LLC | 7.8M | $147.3M | 0.0% | 5.4% | +72.1% |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | 6.2M | $118.2M | 0.0% | 4.3% | -49.7% |
| 5 | WELLINGTON MANAGEMENT GROUP LLP | 6.0M | $114.7M | 0.0% | 4.2% | -34.2% |
| 6 | AMERICAN CENTURY COMPANIES INC | 4.6M | $87.7M | 0.0% | 3.2% | -0.1% |
| 7 | Capital Research Global Investors | 3.9M | $73.4M | 0.0% | 2.7% | -22.9% |
| 8 | Nuveen, LLC | 3.8M | $72.0M | 0.0% | 2.6% | +5.7% |
| 9 | GEODE CAPITAL MANAGEMENT, LLC | 3.8M | $71.9M | 0.0% | 2.6% | +6.6% |
| 10 | JANE STREET GROUP, LLC | 2.2M | $41.7M | 0.0% | 1.5% | +31.8% |
| 11 | MORGAN STANLEY | 2.0M | $37.8M | 0.0% | 1.4% | +114.9% |
| 12 | Qube Research & Technologies Ltd | 2.0M | $37.1M | 0.0% | 1.4% | +195.9% |
| 13 | NORTHERN TRUST CORP | 1.6M | $29.5M | 0.0% | 1.1% | +17.5% |
| 14 | GOLDMAN SACHS GROUP INC | 1.5M | $27.8M | 0.0% | 1% | -2.3% |
| 15 | VICTORY CAPITAL MANAGEMENT INC | 1.2M | $23.4M | 0.0% | 0.9% | -2.5% |
| 16 | Sixth Street Partners Management Company, L.P.NEW | 1.2M | $22.8M | 3.9% | 0.8% | new |
| 17 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 1.2M | $22.8M | 0.0% | 0.8% | +1.9% |
| 18 | BANK OF AMERICA CORP /DE/ | 1.2M | $22.4M | 0.0% | 0.8% | +5.0% |
| 19 | Bank of New York Mellon Corp | 1.2M | $22.1M | 0.0% | 0.8% | +2.1% |
| 20 | VANGUARD FIDUCIARY TRUST CO | 989,092 | $18.8M | 0.0% | 0.7% | -0.8% |
| 21 | MILLENNIUM MANAGEMENT LLC | 764,819 | $14.5M | 0.0% | 0.5% | -38.0% |
| 22 | UBS Group AG | 746,350 | $14.2M | 0.0% | 0.5% | +65.7% |
| 23 | SILVERCREST ASSET MANAGEMENT GROUP LLC | 707,749 | $13.4M | 0.1% | 0.5% | +14.9% |
| 24 | PICTON MAHONEY ASSET MANAGEMENT | 691,471 | $13.1M | 0.1% | 0.5% | +7.5% |
| 25 | Balyasny Asset Management L.P. | 666,554 | $12.7M | 0.0% | 0.5% | -55.6% |
Source: SEC Form 13F-HR filings (institutional managers over $100M in US-listed positions). 13Fs disclose long positions only, up to 45 days after quarter end; each manager's latest filed quarter is shown per row and dollar values are the manager's filed marks. Aggregates labeled "2026 filers" count only managers whose latest book is a 2026 quarter. Related: valuation · options positioning · supply chain. Research, not investment advice.