MGNI
Magnite, Inc. · Communication Services · Advertising Agencies
Momentum inputs (comparable managers):
holder breadth -7.1% ·
share flow -0.4% ·
net new positions -7.7%
· formula
Broad distribution: falling shares and fewer holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q2 2025
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q3 2026 | 1 | -1 | 24.25K | $617,290 | n/a | −2 |
| Q2 2026 | 101 | -1 | 92.35M | $1.75B | +9 | −12 |
| Q1 2026 | 107 | +5 | 86.26M | $1.03B | +8 | −3 |
| Q4 2025 | 102 | -2 | 99.58M | $1.62B | n/a | −2 |
| Q3 2025 | 19 | +4 | 66.20M | $1.44B | +4 | −1 |
| Q2 2025 | 13 | -1 | 54.58M | $1.32B | +1 | −2 |
| Q1 2025 | 11 | -1 | 13.35M | $152.28M | n/a | −1 |
| Q4 2024 | 12 | +1 | 14.99M | $238.72M | +1 | n/a |
| Q3 2024 | 10 | 0 | 14.78M | $204.65M | n/a | n/a |
| Q2 2024 | 10 | n/a | 8.59M | $114.16M | n/a | n/a |
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | Fidelity (FMR) ✦ | 17.19M | n/a | $414.52M | 0.0% | n/c | 1 | SEC ↗ ×6 |
| 2 | The Vanguard Group ✦ (passive) | 13.56M | n/a | $327.12M | 0.0% | n/c | 1 | SEC ↗ ×5 |
| 3 | BlackRock ✦ (passive) | 10.70M | n/a | $258.04M | 0.0% | n/c | 1 | SEC ↗ ×17 |
| 4 | Wellington Management ✦ | 5.45M | -7.7% | $131.40M | 0.0% | ▼ Trim | 5 | SEC ↗ ×10 |
| 5 | Geode Capital Management ✦ (passive) | 3.22M | +6.0% | $77.60M | 0.0% | ▲ Add | 5 | SEC ↗ ×2 |
| 6 | State Street Global Advisors ✦ (passive) | 3.05M | +5.2% | $73.65M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 7 | Citadel Advisors ✦ | 835.10K | +40.8% | $20.14M | 0.0% | ▲ Add | 5 | SEC ↗ ×2 |
| 8 | Two Sigma Investments ✦ | 237.83K | +344.1% | $5.74M | 0.0% | ▲ Add | 5 | SEC ↗ |
| 9 | T. Rowe Price ✦ | 117.60K | +18.7% | $2.84M | 0.0% | ▲ Add | 5 | SEC ↗ |
| 10 | Norges Bank ✦ (passive) | 108.72K | -50.4% | $2.62M | 0.0% | ▼ Trim | 5 | SEC ↗ |
| 11 | GAMCO Investors ✦ | 59.58K | -24.4% | $1.44M | 0.0% | ▼ Trim | 5 | SEC ↗ |
| 12 | D. E. Shaw & Co. ✦ | 31.95K | New | $770,562 | 0.0% | New | 1 | SEC ↗ ×2 |
| 13 | AQR Capital Management ✦ | 20.96K | +47.9% | $505,556 | 0.0% | ▲ Add | 3 | SEC ↗ ×4 |
“Their weight” = the position's share of that manager's reported 13F equity value: the conviction measure. ✦ = curated manager.
New buyers
| D. E. Shaw & Co. | $770,562 | 0.0% |
Exited
| Millennium Management | $4.96M | was 0.0% |
| Marshall Wace | $153,669 | was 0.0% |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 295 holders, 130.58M shares, $1.54B reported. This is a different, older period than the tracked-universe figures above and the two are never mixed.
What else this security's tracked holders most often hold: shared-ownership counts, not fundamental relationships.
Open-market purchases (P)
No open-market insider purchases in our coverage window.
Open-market sales (S)
Director · 12.50K sh · $316,125
Director · 37.34K sh · $981,216
Director · 7.50K sh · $198,750
Director · 10.36K sh · $246,225
Officer · 1.17K sh · $27,960
Officer · 14.00K sh · $335,928
Director · 5.00K sh · $117,650
Officer · 40.00K sh · $936,400
Officer · 11.10K sh · $260,406
Officer · 32.28K sh · $762,895
Awards, exercises and tax withholding are never counted as buys or sales here. Methodology