Magnite
MGNI
316 hedge funds and large institutions have $3B invested in Magnite in 2025 Q3 according to their latest regulatory filings, with 72 funds opening new positions, 82 increasing their positions, 125 reducing their positions, and 41 closing their positions.
76% more first-time investments, than exits
New positions opened: 72 | Existing positions closed: 41
47% more call options, than puts
Call options by funds: $132M | Put options by funds: $89.4M
10% more funds holding
Funds holding: 286 → 316 (+30)
7.28% less ownership
Funds ownership: 104.18% → 96.9% (-7.3%)
15% less capital invested
Capital invested by funds: $3.54B → $3B (-$540M)
31% less funds holding in top 10
Funds holding in top 10: 16 → 11 (-5)
34% less repeat investments, than reductions
Existing positions increased: 82 | Existing positions reduced: 125
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
T. Rowe Price Associates
Baltimore,
Maryland
|
+$57.4M |
| 2 |
BGC
Blue Grotto Capital
Atlanta,
Georgia
|
+$29.8M |
| 3 |
Vanguard Group
Malvern,
Pennsylvania
|
+$25.8M |
| 4 |
T. Rowe Price Investment Management
Baltimore,
Maryland
|
+$21M |
| 5 |
Morgan Stanley
New York
|
+$20.7M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Capital Research Global Investors
Los Angeles,
California
|
-$140M |
| 2 |
SSA
Schonfeld Strategic Advisors
New York
|
-$45.8M |
| 3 |
EC
Edenbrook Capital
Mt. Kisco,
New York
|
-$35.4M |
| 4 |
Dimensional Fund Advisors
Austin,
Texas
|
-$31.5M |
| 5 |
UBS Group
Zurich,
Switzerland
|
-$30.9M |
MGNI Hedge Fund Activity: Q3 2025 in Review
316 of the 7,619 institutional investors tracked by Wall St. Rank reported a position in Magnite (MGNI) for Q3 2025, worth a combined $3B — down 15% from $3.54B a quarter earlier.
Buyers outnumbered sellers: 72 funds opened new MGNI positions and 41 closed out — a net gain of 31 holders — while 82 added to existing stakes and 125 trimmed.
The largest buyer was T. Rowe Price Associates, adding an estimated $57.4M. The largest seller was Capital Research Global Investors, cutting an estimated $140M.
- 316 institutional investors held Magnite (MGNI) as of Q3 2025, up from 286 in Q2 2025.
- Funds reported $3B of Magnite stock for Q3 2025, down 15% quarter-over-quarter.
- 72 funds opened new Magnite positions in Q3 2025 and 41 closed out, a net change of +31 holders.
- The largest Magnite buyer in Q3 2025 was T. Rowe Price Associates, an estimated $57.4M added.
- The largest Magnite seller in Q3 2025 was Capital Research Global Investors, an estimated $140M sold.
Based on aggregated 13F filings for Q3 2025.