MGNI
Magnite, Inc. · Communication Services · Advertising Agencies
Momentum inputs (comparable managers):
holder breadth +26.7% ·
share flow +8.0% ·
net new positions +15.8%
— formula
Broad accumulation — rising shares across more holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q3 2025
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q2 2026 | 103 | -1 | 93.04M | $1.77B | +9 | −10 |
| Q1 2026 | 107 | +5 | 86.26M | $1.03B | +8 | −3 |
| Q4 2025 | 102 | -2 | 99.58M | $1.62B | — | −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 | — | −1 |
| Q4 2024 | 12 | +1 | 14.99M | $238.72M | +1 | — |
| Q3 2024 | 10 | 0 | 14.78M | $204.65M | — | — |
| Q2 2024 | 10 | — | 8.59M | $114.16M | — | — |
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | Fidelity (FMR) ✦ | 17.14M | -0.3% | $373.33M | 0.0% | ▼ Trim | 2 | SEC ↗ ×6 |
| 2 | The Vanguard Group ✦ (passive) | 14.65M | +8.1% | $319.17M | 0.0% | ▲ Add | 2 | SEC ↗ ×5 |
| 3 | BlackRock ✦ (passive) | 11.41M | +6.7% | $248.58M | 0.0% | ▲ Add | 2 | SEC ↗ ×15 |
| 4 | Wellington Management ✦ | 5.14M | -5.6% | $112.05M | 0.0% | ▼ Trim | 6 | SEC ↗ ×7 |
| 5 | Geode Capital Management ✦ (passive) | 3.40M | +5.7% | $74.04M | 0.0% | ▲ Add | 6 | SEC ↗ ×2 |
| 6 | State Street Global Advisors ✦ (passive) | 3.13M | +2.4% | $68.10M | 0.0% | ▲ Add | 4 | SEC ↗ |
| 7 | T. Rowe Price ✦ | 2.55M | +2066.2% | $55.49M | 0.0% | ▲ Add | 6 | SEC ↗ ×2 |
| 8 | JPMorgan Chase ✦ | 2.42M | — | $52.68M | 0.0% | n/c | 1 | SEC ↗ ×10 |
| 9 | Goldman Sachs Group ✦ | 2.39M | — | $51.95M | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 10 | Morgan Stanley ✦ | 2.05M | — | $44.57M | 0.0% | n/c | 1 | SEC ↗ ×7 |
| 11 | Millennium Management ✦ | 676.35K | New | $14.73M | 0.0% | New | 1 | SEC ↗ ×2 |
| 12 | Point72 Asset Management ✦ | 305.32K | New | $6.65M | 0.0% | New | 1 | SEC ↗ |
| 13 | Two Sigma Investments ✦ | 300.43K | +26.3% | $6.54M | 0.0% | ▲ Add | 6 | SEC ↗ |
| 14 | D. E. Shaw & Co. ✦ | 211.43K | +561.8% | $4.61M | 0.0% | ▲ Add | 2 | SEC ↗ ×2 |
| 15 | Citadel Advisors ✦ | 169.56K | -79.7% | $3.69M | 0.0% | ▼ Trim | 6 | SEC ↗ |
| 16 | Bridgewater Associates ✦ | 145.67K | New | $3.17M | 0.0% | New | 1 | SEC ↗ |
| 17 | GAMCO Investors ✦ | 56.47K | -5.2% | $1.23M | 0.0% | ▼ Trim | 6 | SEC ↗ |
| 18 | AQR Capital Management ✦ | 48.07K | +129.3% | $1.05M | 0.0% | ▲ Add | 4 | SEC ↗ ×4 |
| 19 | Marshall Wace ✦ | 12.65K | New | $275,473 | 0.0% | New | 1 | SEC ↗ |
“Their weight” = the position's share of that manager's reported 13F equity value — the conviction measure. ✦ = curated manager.
New buyers
| Millennium Management | $14.73M | 0.0% |
| Point72 Asset Management | $6.65M | 0.0% |
| Bridgewater Associates | $3.17M | 0.0% |
| Marshall Wace | $275,473 | 0.0% |
Exited
| Norges Bank | $2.62M | 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 · 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
Officer · 1.04K sh · $26,075
Awards, exercises and tax withholding are never counted as buys or sales here. Methodology