XTX Topco’s Magnite MGNI Stock Holding History

XTX Topco’s Portfolio MGNI Stock Details MGNI Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$1.74M	Buy	146,591 +99,928	+214%	+$1.34M	0.03%	944
2025 Q4	$757K	Sell	46,663 -34,782	-43%	-$577K	0.02%	1247
2025 Q3	$1.77M	Buy	+81,445	New	+$1.92M	0.09%	252
2025 Q2	–	Sell	-135,118	Closed	-$1.54M	–	2853
2025 Q1	$1.54M	Buy	+135,118	New	+$2.15M	0.08%	348
2024 Q4	–	Sell	-15,889	Closed	-$220K	–	2688
2024 Q3	$220K	Buy	+15,889	New	+$216K	0.02%	1385
2022 Q4	–	Sell	-34,413	Closed	-$226K	–	1352
2022 Q3	$226K	Buy	+34,413	New	+$277K	0.06%	706
2021 Q3	–	Sell	-8,005	Closed	-$271K	–	914
2021 Q2	$271K	Buy	+8,005	New	+$271K	0.09%	424

Other funds holding MGNI

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

Wellington Management Group Boston, Massachusetts $535B AUM 26.23% 1-Year Est. Return

VPM

Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

Capital Research Global Investors Los Angeles, California $645B AUM 30.41% 1-Year Est. Return

Boston Partners Boston, Massachusetts $95.5B AUM 28.4% 1-Year Est. Return

American Century Companies Kansas City, Missouri $194B AUM 35% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

Dimensional Fund Advisors Austin, Texas $481B AUM 30.42% 1-Year Est. Return

Nuveen Charlotte, North Carolina $369B AUM 31.66% 1-Year Est. Return

XTX Topco's MGNI Position: Q1 2026 in Review

XTX Topco increased its Magnite (MGNI) stake by 214% in Q1 2026, buying an estimated $1.34M and bringing the position to 146,591 shares worth $1.74M. The position accounts for 0.03% of the portfolio, ranked #944.

XTX Topco first reported a position in MGNI in Q2 2021 and has held it in 7 quarters since. The position peaked at $1.77M in Q3 2025. 297 funds tracked by Wall St. Rank hold MGNI as of Q1 2026.

XTX Topco held 146,591 shares of Magnite worth $1.74M as of Q1 2026.
XTX Topco bought 99,928 Magnite shares in Q1 2026, an estimated $1.34M.
Magnite made up 0.03% of XTX Topco's portfolio in Q1 2026, its #944 holding.
XTX Topco first reported a position in Magnite in Q2 2021 and has held it in 7 quarters since.
XTX Topco's Magnite position peaked at $1.77M in Q3 2025.
297 funds tracked by Wall St. Rank held Magnite as of Q1 2026.

Based on XTX Topco's 13F filing for Q1 2026, filed 15 May 2026.