Ranked by reported Q2 2026 13F market value
Share of total reported institutional value in MGNI held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 12.7M | $241.3M | +9.1% | 8.877% | 0.00% |
| 2 | VANGUARD PORTFOLIO MANAGEMENT LLC | 8.2M | $155.6M | +6.1% | 5.724% | 0.01% |
| 3 | FMR LLC | 7.8M | $147.3M | +72.2% | 5.418% | 0.01% |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | 6.2M | $118.2M | +0.6% | 4.347% | 0.00% |
| 5 | WELLINGTON MANAGEMENT GROUP LLP | 6.0M | $114.7M | -34.2% | 4.221% | 0.02% |
| 6 | DIMENSIONAL FUND ADVISORS LP | 5.3M | $99.8M | +32.0% | 3.673% | 0.02% |
| 7 | Boston Partners | 5.0M | $95.9M | +6.2% | 3.501% | 0.09% |
| 8 | AMERICAN CENTURY COMPANIES INC | 4.6M | $87.7M | -0.1% | 3.228% | 0.04% |
| 9 | Capital Research Global Investors | 3.9M | $73.4M | -22.9% | 2.702% | 0.01% |
| 10 | Nuveen, LLC | 3.8M | $72.0M | +5.7% | 2.650% | 0.02% |
| 11 | GEODE CAPITAL MANAGEMENT, LLC | 3.8M | $71.9M | +6.7% | 2.646% | 0.00% |
| 12 | Edenbrook Capital, LLC | 3.6M | $67.5M | +4.6% | 2.483% | 13.60% |
| 13 | STATE STREET CORP | 3.5M | $67.0M | +11.5% | 2.464% | 0.00% |
| 14 | 325 CAPITAL LLC | 3.4M | $64.8M | +70.2% | 2.383% | 15.44% |
| 15 | Nine Ten Capital Management LLC | 3.3M | $61.9M | -6.3% | 2.277% | 19.26% |
| 16 | Granahan Investment Management, LLC | 3.1M | $58.5M | +20.8% | 2.153% | 2.09% |
| 17 | CANADA PENSION PLAN INVESTMENT BOARD | 3.0M | $56.8M | +6403.7% | 2.091% | 0.03% |
| 18 | JANE STREET GROUP, LLC | 2.4M | $45.3M | +33.7% | 1.668% | 0.00% |
| 19 | Park West Asset Management LLC | 2.3M | $42.7M | +276.0% | 1.571% | 2.91% |
| 20 | Caption Management, LLC | 2.0M | $38.0M | +5.0% | 1.396% | 0.18% |
| 21 | MORGAN STANLEY | 2.0M | $37.8M | +114.9% | 1.391% | 0.00% |
| 22 | CITADEL ADVISORS LLC | 2.0M | $37.6M | -9.9% | 1.382% | 0.00% |
| 23 | Qube Research & Technologies Ltd | 2.0M | $37.1M | +195.9% | 1.366% | 0.03% |
| 24 | Blue Grotto Capital, LLC | 1.7M | $32.4M | +28.4% | 1.192% | 2.70% |
| 25 | KENNEDY CAPITAL MANAGEMENT LLC | 1.7M | $31.6M | -5.0% | 1.164% | 0.56% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in MGNI — a direct measure of their conviction.
Filings activity in MGNI during Q2 2026, grouped by how each filer changed its position.
Institutions that opened a new MGNI position in Q2 2026
Institutions that fully closed their MGNI position in Q2 2026
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q2 2026 | 310 | +4.0% | 104.25% | +8.04 pp | $2.82B | +74% |
| Q1 2026 | 298 | 2.9% | 96.21% | 5.52 pp | $1.62B | 30% |
| Q4 2025 | 307 | 2.2% | 101.73% | 0.68 pp | $2.33B | 25% |
| Q3 2025 | 314 | +12% | 102.41% | 2.72 pp | $3.09B | 14% |
| Q2 2025 | 280 | 1.1% | 105.13% | +8.23 pp | $3.59B | +133% |
| Q1 2025 | 283 | +3.3% | 96.90% | +9.03 pp | $1.54B | 20% |
| Q4 2024 | 274 | +2.2% | 87.87% | +0.63 pp | $1.94B | +17% |
| Q3 2024 | 268 | — | 87.24% | — | $1.66B | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying MGNI stock.
Based on Q2 2026 13F filings, institutional ownership of Magnite, Inc. stands at 104.3%, held across 310 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of MGNI, with approximately 12,713,156 shares worth $0.24B as of Q2 2026.
Yes — 2 widely-followed marquee investors appear among the top 25 institutional holders of MGNI, including JANE STREET GROUP, LLC, CITADEL ADVISORS LLC.
Our composite Smart Money Score for MGNI is 67 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
48 institutions opened new positions in MGNI during Q2 2026, while 36 fully exited. 231 added to existing positions and 23 trimmed.
MGNI institutional ownership rose by 8.04 percentage points quarter-over-quarter, with a net change of +12 holders.
The top 10 institutions account for 42.8% of all reported 13F value in MGNI, and the top 25 account for 69.4%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Magnite, Inc. (MGNI) Institutional Ownership