AI summary pending
View Full Filing (SEC EDGAR)Magnite Inc
$25.45+0.8%
+$391.0M
Net Activity
+11.71% total shares
Institutions Holding
315
Popularity Rank
#2018
Avg Weight
0.43%
Total Value
$3.0B
Market Cap
$3.9B
315 institutions currently hold MGNI, with 180 net buyers and 126 net sellers this quarter.
Institutional Moves (Q2 2026)
Majority Increased
Based on recent trading activity
Net Selling Institutions
126
Net Buying Institutions
180
Top 5 by Value
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Across its top 20 institutional holders, MGNI's holder base skews toward low-concentration, low-turnover investors on average (avg. concentration score 13/100, avg. turnover score 39/100).
MGNI ranks #2018 out of 37696 tracked stocks by institutional interest — one of the most closely watched names in our coverage.
MGNI is a top-conviction position for Nine Ten Capital Management LLC — at 19.3% of their entire disclosed 13F portfolio, it's one of their largest single bets, not just a passing allocation.
The largest dollar stake in MGNI belongs to BlackRock, Inc., but the position matters far more to Nine Ten Capital Management LLC, who has 19.3% of their own portfolio riding on it — a reminder that the biggest holder by size and the holder with the biggest bet aren't always the same fund.
Kopion Asset Management, LLC has added to its MGNI position for two straight quarters, increasing it by $2.9M to reach $13.1M today.
MGNI is up 0.8% today, and institutions have been net buyers of $391.0M this quarter — today's price move and the underlying institutional flow are pointing the same direction.
MGNI posted net income of $166.9M over the trailing twelve months, and currently trades at a P/E of 23.4.
+$726.0M
Total Buy Value
$272.7M
Total Sell Value
180
Net Buyers
126
Net Sellers
MGNI
Q2 2026
Top 5 Institutional Movers
MGNI does not currently have enough recent insider (Form 4) trading activity to compute a convergence signal against its 13F institutional flows.
13F data as of 2026-09-30 quarterly filings. Note: many large institutions file close to the 45-day post-quarter deadline, so early-quarter flow figures can shift substantially as more filings arrive.
24
Filings (90d)
$16.33M
Total Est. Value
714K shares
Planned Shares
| Filer | Filing Date | Est. Value |
|---|---|---|
| PAUL CAINE | 2026-09-17 | $476K |
| Douglas S. Knopper & Abigail L. Knopper TTEES of the Knopper Joint Mgmt Trust 11/15/13 | 2026-09-17 | $888K |
| DAVID BUONASERA | 2026-09-14 | $28K |
| ROBERT SPILLANE | 2026-09-14 | $246K |
| KATHERYN EVANS | 2026-09-11 | $336K |
| AARON SALTZ | 2026-09-10 | $1.41M |
| PAUL CAINE | 2026-09-10 | $236K |
| KATHERYN EVANS | 2026-09-09 | $260K |
| KATHERYN EVANS | 2026-09-08 | $763K |
| DAVID BUONASERA | 2026-09-02 | $26K |
Form 144 is a planned sale notice, not an executed transaction. Form 144 Tracker。
0
Active 5%+ Holders
| Reporting Person | Type | Filing Date | % of Class |
|---|---|---|---|
| Wellington Management Group LLP | 13G/A | 2026-08-13 | 4.2% |
3
Filings (14d)
AI summary pending
View Full Filing (SEC EDGAR)AI summary pending
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View Full Filing (SEC EDGAR)55955D100, 559534PAT
The most-added stocks by 13F institutions this quarter
Institutions Holding
6,278
Total reported value
$2.2T
3254 13F institutions increased their position this quarter
Institutions Holding
6,025
Total reported value
$3.6T
3054 13F institutions increased their position this quarter
Institutions Holding
6,188
Total reported value
$1.8T
2995 13F institutions increased their position this quarter
The most widely held stocks tracked across all 13F institutions
Institutions Holding
4,716
Total reported value
$473.6B
Held by 4716 institutions — one of the most-tracked stocks on AlphaSMO
Institutions Holding
4,662
Total reported value
$986.0B
Held by 4662 institutions — one of the most-tracked stocks on AlphaSMO
Institutions Holding
4,610
Total reported value
$529.1B
Held by 4610 institutions — one of the most-tracked stocks on AlphaSMO
Access MGNI's institutional ownership data programmatically:
REST API
curl https://alphasmo.com/api/v1/market/stock/MGNICLI
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