Magnite
MGNI
304 hedge funds and large institutions have $2.22B invested in Magnite in 2025 Q4 according to their latest regulatory filings, with 56 funds opening new positions, 122 increasing their positions, 93 reducing their positions, and 55 closing their positions.
49% more call options, than puts
Call options by funds: $97.9M | Put options by funds: $65.5M
31% more repeat investments, than reductions
Existing positions increased: 122 | Existing positions reduced: 93
2% more first-time investments, than exits
New positions opened: 56 | Existing positions closed: 55
1.75% less ownership
Funds ownership: 96.9% → 95.15% (-1.7%)
4% less funds holding
Funds holding: 316 → 304 (-12)
9% less funds holding in top 10
Funds holding in top 10: 11 → 10 (-1)
26% less capital invested
Capital invested by funds: $3B → $2.22B (-$785M)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Capital Research Global Investors
Los Angeles,
California
|
+$98.6M |
| 2 |
Wellington Management Group
Boston,
Massachusetts
|
+$57.8M |
| 3 |
OAM
Ophir Asset Management
Sydney,
Australia
|
+$39.6M |
| 4 |
NSGL
No Street GP LP
San Francisco,
California
|
+$24.5M |
| 5 |
3C
325 Capital
New York
|
+$22.5M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Fidelity Investments
Boston,
Massachusetts
|
-$173M |
| 2 |
DCM
Driehaus Capital Management
Chicago,
Illinois
|
-$33M |
| 3 |
T. Rowe Price Associates
Baltimore,
Maryland
|
-$30.5M |
| 4 |
T. Rowe Price Investment Management
Baltimore,
Maryland
|
-$19.4M |
| 5 |
GIM
Granahan Investment Management
Waltham,
Massachusetts
|
-$12.6M |
MGNI Hedge Fund Activity: Q4 2025 in Review
304 of the 8,267 institutional investors tracked by Wall St. Rank reported a position in Magnite (MGNI) for Q4 2025, worth a combined $2.22B — down 26% from $3B a quarter earlier.
Buyers outnumbered sellers: 56 funds opened new MGNI positions and 55 closed out — a net gain of 1 holder — while 122 added to existing stakes and 93 trimmed.
The largest buyer was Capital Research Global Investors, adding an estimated $98.6M. The largest seller was Fidelity Investments, cutting an estimated $173M.
- 304 institutional investors held Magnite (MGNI) as of Q4 2025, down from 316 in Q3 2025.
- Funds reported $2.22B of Magnite stock for Q4 2025, down 26% quarter-over-quarter.
- 56 funds opened new Magnite positions in Q4 2025 and 55 closed out, a net change of +1 holder.
- The largest Magnite buyer in Q4 2025 was Capital Research Global Investors, an estimated $98.6M added.
- The largest Magnite seller in Q4 2025 was Fidelity Investments, an estimated $173M sold.
Based on aggregated 13F filings for Q4 2025.