Magnetar Financial’s Costco COST Stock Holding History

Magnetar Financial’s Portfolio COST Stock Details COST Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$962K	Sell	965 -205	-18%	-$200K	0.01%	488
2025 Q4	$1.01M	Buy	+1,170	New	+$1.06M	0.01%	437
2022 Q1	–	Sell	-1,961	Closed	-$1.11M	–	1370
2021 Q4	$1.11M	Sell	1,961 -6,066	-76%	-$3.11M	0.01%	778
2021 Q3	$3.61M	Buy	+8,027	New	+$3.53M	0.04%	470
2020 Q4	–	Sell	-4,954	Closed	-$1.76M	–	756
2020 Q3	$1.76M	Buy	+4,954	New	+$1.66M	0.03%	269
2020 Q1	–	Sell	-5,404	Closed	-$1.59M	–	504
2019 Q4	$1.59M	Buy	+5,404	New	+$1.61M	0.03%	169
2018 Q3	–	Sell	-976	Closed	-$204K	–	546
2018 Q2	$204K	Sell	976 -1,619	-62%	-$320K	﹤0.01%	459
2018 Q1	$489K	Sell	2,595 -3,302	-56%	-$623K	0.01%	342
2017 Q4	$1.1M	Buy	+5,897	New	+$1.02M	0.02%	207
2016 Q4	–	Sell	-13,199	Closed	-$2.01M	–	99
2016 Q3	$2.01M	Buy	+13,199	New	+$2.13M	0.03%	178
2015 Q3	–	Sell	-3,227	Closed	-$436K	–	422
2015 Q2	$436K	Buy	+3,227	New	+$464K	0.01%	306

Other funds holding COST

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

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

Invesco Atlanta, Georgia $1.02T AUM 30.18% 1-Year Est. Return

VPM

Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM

Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return

Morgan Stanley New York $1.66T AUM 25.57% 1-Year Est. Return

Bank of America Charlotte, North Carolina $1.37T AUM 24.88% 1-Year Est. Return

DAM

Diamant Asset Management Ridgefield, Connecticut $137B AUM 18.02% 1-Year Est. Return

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

Magnetar Financial's COST Position: Q1 2026 in Review

Magnetar Financial reduced its Costco (COST) stake by 18% in Q1 2026, selling an estimated $200K and leaving 965 shares worth $962K. The position accounts for 0.01% of the portfolio, ranked #488.

Magnetar Financial first reported a position in COST in Q2 2015 and has held it in 11 quarters since. The position peaked at $3.61M in Q3 2021. 4,237 funds tracked by Wall St. Rank hold COST as of Q1 2026.

Magnetar Financial held 965 shares of Costco worth $962K as of Q1 2026.
Magnetar Financial sold 205 Costco shares in Q1 2026, an estimated $200K.
Costco made up 0.01% of Magnetar Financial's portfolio in Q1 2026, its #488 holding.
Magnetar Financial first reported a position in Costco in Q2 2015 and has held it in 11 quarters since.
Magnetar Financial's Costco position peaked at $3.61M in Q3 2021.
4,237 funds tracked by Wall St. Rank held Costco as of Q1 2026.

Based on Magnetar Financial's 13F filing for Q1 2026, filed 13 May 2026.