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MGNI · Magnite, Inc.

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$22.89 -0.60 (-2.55%) At close · Sep 1
Market Cap
$3.28B
Shares
143.42M

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 309
Total Value: $2,836,659,978
Total Shares: 149,455,387
Showing 1–100 of 327 holdings by value · page 1 of 4

Institutional Ownership Trend

26 quarters

Holder Concentration

Across 309 13F filers · Δ vs Mar 31, 2026
Top Holder
8.5%
Sep 2023 → Jun 2026 · range 8.5% – 12.1%
+0.1 pts
Top 5
27.4%
Sep 2023 → Jun 2026 · range 27.4% – 39.7%
−1.5 pts
Top 10
42.5%
Sep 2023 → Jun 2026 · range 42.5% – 57.8%
−1.9 pts
HHI
276
Sep 2023 → Jun 2026 · range 276 – 467
Broadly held−15

Quarterly Activity

vs Mar 31, 2026
New
55
Increased
116
Decreased
90
Sold Out
44
Unchanged
48
Holder count: +11
Institutional value: +73.2%
Shares held: +8.4%

Top Buyers

vs Mar 31, 2026
Institution Added Now Holds Open

Top Sellers

vs Mar 31, 2026
Institution Sold Now Holds Open

Top New Positions

vs Mar 31, 2026
Institution Acquired Value (USD) Open

Top Sold-Out Positions

vs Mar 31, 2026
Institution Previously Held Last Value (USD) Open
Showing 100 of 327
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Holder Value (USD) % of 13F Shares Open
Key facts CIK 1595974 CUSIP 55955D100 13F (30d) 245 filings 243 filers Visit website Investor relations