Magnite, Inc.
MX ˙ BMV ˙ US55955D1000
SecurityMX:MGNI / Magnite, Inc.
InstitutionState Street Corp
Latest Disclosed Ownership3,163,139 shares
Latest Disclosed Value $ 37,578,091
State Street Corp reports 0.67% increase in ownership of MGNI / Magnite, Inc.

On May 15, 2026 - State Street Corp filed a 13F-HR form disclosing ownership of 3,163,139 shares of Magnite, Inc. (MX:MGNI) valued at $37,578,091 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 3,141,991 shares of Magnite, Inc.. This represents a change in shares of 0.67% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F MAGNITE COM 55955D100 3,163,139 21,148 0.67 37,578 -26.31 0.0013
2026-02-13 2025-12-31 13F MAGNITE COM 55955D100 3,141,991 15,201 0.49 50,995 -25.12 0.0017
2025-11-14 2025-09-30 13F MAGNITE COM 55955D100 3,126,790 73,183 2.40 68,101 -7.54 0.0024
2025-08-14 2025-06-30 13F MAGNITE COM 55955D100 3,053,607 150,547 5.19 73,653 122.36 0.0028
2025-05-15 2025-03-31 13F MAGNITE COM 55955D100 2,903,060 -39,070 -1.33 33,124 -29.28 0.0014
2025-02-14 2024-12-31 13F MAGNITE COM 55955D100 2,942,130 -111,474 -3.65 46,839 10.75 0.0018
2024-11-14 2024-09-30 13F MAGNITE COM 55955D100 3,053,604 -67,346 -2.16 42,292 1.96 0.0017
2024-08-14 2024-06-30 13F MAGNITE COM 55955D100 3,120,950 76,088 2.50 41,477 26.72 0.0018
2024-05-15 2024-03-31 13F MAGNITE COM 55955D100 3,044,862 78,938 2.66 32,732 18.16 0.0015
2024-02-14 2023-12-31 13F MAGNITE COM 55955D100 2,965,924 164,539 5.87 27,702 31.15 0.0013
2023-11-14 2023-09-30 13F MAGNITE COM 55955D100 2,801,385 41,527 1.50 21,122 -43.93 0.0012
2023-08-14 2023-06-30 13F MAGNITE COM 55955D100 2,759,858 28,680 1.05 37,672 48.96 0.0020
2023-05-15 2023-03-31 13F MAGNITE COM 55955D100 2,731,178 49,408 1.84 25,290 -10.95 0.0014
2023-05-15 2022-12-31 13F/A-99 MAGNITE COM 55955D100 2,681,770 -53,783 -1.97 28,400 58.01 0.0017
2023-05-15 2022-12-31 13F MAGNITE COM 55955D100 2,681,770 -53,783 28,400 0.0017
2022-11-15 2022-09-30 13F MAGNITE COM 55955D100 2,735,553 24,201 0.89 17,973 -25.35 0.0011
2022-08-15 2022-06-30 13F MAGNITE COM 55955D100 2,711,352 19,854 0.74 24,077 -32.28 0.0014
2022-05-16 2022-03-31 13F MAGNITE COM 55955D100 2,691,498 72,612 2.77 35,555 -22.42 0.0018
2022-02-14 2021-12-31 13F MAGNITE COM 55955D100 2,618,886 233,025 9.77 45,831 -31.39 0.0022
2021-11-15 2021-09-30 13F MAGNITE COM 55955D100 2,385,861 257,167 12.08 66,804 -7.26 0.0035
2021-08-16 2021-06-30 13F MAGNITE COM 55955D100 2,128,694 -136,415 -6.02 72,035 -23.57 0.0038
2021-07-09 2021-03-31 13F/A-1 MAGNITE COM 55955D100 2,265,109 -281,527 -11.05 94,251 20.51 0.0054
2021-05-17 2021-03-31 13F MAGNITE COM 55955D100 2,265,109 -281,527 94,251 0.0054
2021-02-16 2020-12-31 13F MAGNITE COM 55955D100 2,546,636 -281,841 -9.96 78,207 298.12 0.0048
2020-11-10 2020-09-30 13F MAGNITE COM 55955D100 2,828,477 2,828,477 19,644 0.0013
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.