Magnite, Inc.
MX ˙ BMV ˙ US55955D1000
SecurityMX:MGNI / Magnite, Inc.
InstitutionStifel Financial Corp
Latest Disclosed Ownership46,601 shares
Latest Disclosed Value $ 553,617
Stifel Financial Corp reports 20.72% decrease in ownership of MGNI / Magnite, Inc.

On May 12, 2026 - Stifel Financial Corp filed a 13F-HR form disclosing ownership of 46,601 shares of Magnite, Inc. (MX:MGNI) valued at $553,617 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 58,782 shares of Magnite, Inc.. This represents a change in shares of -20.72% 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)
2026-05-12 2026-03-31 13F MAGNITE COM 55955D100 46,601 -12,181 -20.72 554 -42.03 0.0001
2026-02-13 2025-12-31 13F MAGNITE COM 55955D100 58,782 -349 -0.59 954 -25.87 0.0009
2025-11-12 2025-09-30 13F MAGNITE COM 55955D100 59,131 -19,668 -24.96 1,288 -32.26 0.0012
2025-08-14 2025-06-30 13F MAGNITE COM 55955D100 78,799 24,504 45.13 1,901 206.95 0.0018
2025-05-14 2025-03-31 13F MAGNITE COM 55955D100 54,295 -1,827 -3.26 620 -30.68 0.0007
2025-02-13 2024-12-31 13F MAGNITE COM 55955D100 56,122 9,620 20.69 893 38.66 0.0009
2024-11-14 2024-09-30 13F MAGNITE COM 55955D100 46,502 21,472 85.79 644 93.98 0.0007
2024-08-13 2024-06-30 13F MAGNITE COM 55955D100 25,030 25,030 333 0.0004
2024-02-12 2023-12-31 13F MAGNITE COM 55955D100 0 -10,955 -100.00 0 -100.00
2023-11-13 2023-09-30 13F MAGNITE COM 55955D100 10,955 -253 -2.26 83 -46.05 0.0001
2023-08-14 2023-06-30 13F MAGNITE COM 55955D100 11,208 11,208 153 0.0002
2022-05-13 2022-03-31 13F MAGNITE COM 55955D100 0 -31,862 -100.00 0 -100.00
2022-02-14 2021-12-31 13F MAGNITE COM 55955D100 31,862 -8,211 -20.49 558 -50.27 0.0007
2021-11-15 2021-09-30 13F MAGNITE COM 55955D100 40,073 7,796 24.15 1,122 2.75 0.0016
2021-08-13 2021-06-30 13F MAGNITE COM 55955D100 32,277 -429 -1.31 1,092 -19.76 0.0016
2021-05-14 2021-03-31 13F MAGNITE COM 55955D100 32,706 14,694 81.58 1,361 146.11 0.0022
2021-02-12 2020-12-31 13F MAGNITE COM 55955D100 18,012 18,012 553 0.0010
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.