Who owns MAGNITE, INC.?
Prices and market caps: Cboe delayed data, at least 15 minutes delayed. Not real-time. Fundamentals from company filings.
Institutional ownership of MGNI from SEC Form 13F filings across 311 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.
As of the 2026-06-30 reporting period, 311 institutions disclosed 141.9M shares of MAGNITE, INC. worth $2.69B — about 99.2% of shares outstanding; the largest disclosed holder is BlackRock, Inc.. Source: SEC Form 13F filings, parsed by EvidInvest.
311
13F holders
$2.69B
value, 2026 filers
99.2%
of shares outstanding (141.9M sh)
57
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% | 4.4% | +0.6% |
| 5 | WELLINGTON MANAGEMENT GROUP LLP | 6.0M | $114.7M | 0.0% | 4.2% | -34.2% |
| 6 | DIMENSIONAL FUND ADVISORS LP | 5.3M | $99.8M | 0.0% | 3.7% | +32.0% |
| 7 | Boston Partners | 5.0M | $95.9M | 0.1% | 3.5% | +6.2% |
| 8 | AMERICAN CENTURY COMPANIES INC | 4.6M | $87.7M | 0.0% | 3.2% | -0.1% |
| 9 | Capital Research Global Investors | 3.9M | $73.4M | 0.0% | 2.7% | -22.9% |
| 10 | Nuveen, LLC | 3.8M | $72.0M | 0.0% | 2.7% | +5.7% |
| 11 | GEODE CAPITAL MANAGEMENT, LLC | 3.8M | $71.9M | 0.0% | 2.6% | +6.6% |
| 12 | Edenbrook Capital, LLC | 3.6M | $67.5M | 13.6% | 2.5% | +27.1% |
| 13 | STATE STREET CORP | 3.5M | $67.0M | 0.0% | 2.5% | +11.5% |
| 14 | 325 CAPITAL LLC | 3.4M | $64.8M | 15.4% | 2.4% | +70.2% |
| 15 | Nine Ten Capital Management LLC | 3.3M | $61.9M | 19.3% | 2.3% | -6.3% |
| 16 | Granahan Investment Management, LLC | 3.1M | $58.5M | 2.1% | 2.2% | +20.7% |
| 17 | CANADA PENSION PLAN INVESTMENT BOARD | 3.0M | $56.8M | 0.0% | 2.1% | +6403.7% |
| 18 | JANE STREET GROUP, LLC | 2.2M | $41.7M | 0.0% | 1.5% | +31.8% |
| 19 | Park West Asset Management LLC | 2.0M | $38.0M | 2.6% | 1.4% | +234.2% |
| 20 | MORGAN STANLEY | 2.0M | $37.8M | 0.0% | 1.4% | +114.9% |
| 21 | Qube Research & Technologies Ltd | 2.0M | $37.1M | 0.0% | 1.4% | +195.9% |
| 22 | Blue Grotto Capital, LLC | 1.7M | $32.4M | 2.7% | 1.2% | +28.4% |
| 23 | KENNEDY CAPITAL MANAGEMENT LLC | 1.7M | $31.6M | 0.6% | 1.2% | -4.9% |
| 24 | NORTHERN TRUST CORP | 1.6M | $29.5M | 0.0% | 1.1% | +17.5% |
| 25 | ROYCE & ASSOCIATES LP | 1.5M | $28.0M | 0.2% | 1% | +7.9% |
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.