Mariner’s Costco COST Stock Holding History

Mariner’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
2018 Q2	–	Sell	-400	Closed	-$1K	–	799
2018 Q1	$1K	Buy	+400	New	+$75.5K	﹤0.01%	657

Other funds holding COST

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Invesco Atlanta, Georgia $1.26T AUM 61.52% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return

Bank of America Charlotte, North Carolina $1.55T AUM 33.47% 1-Year Est. Return

Norges Bank Oslo, Norway $1T AUM

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

Mariner's COST Position: Q2 2026 in Review

Mariner reduced its Costco (COST) stake by 3.9% in Q2 2026, selling an estimated $17M and leaving 419,996 shares worth $393M. The position accounts for 0.41% of the portfolio, ranked #42.

Mariner first reported a position in COST in Q2 2013 and has held it in 53 quarters since. The position peaked at $436M in Q1 2026. 4,238 funds tracked by Wall St. Rank hold COST as of Q2 2026.

Mariner held 419,996 shares of Costco worth $393M as of Q2 2026.
Mariner sold 17,092 Costco shares in Q2 2026, an estimated $17M.
Costco made up 0.41% of Mariner's portfolio in Q2 2026, its #42 holding.
Mariner first reported a position in Costco in Q2 2013 and has held it in 53 quarters since.
Mariner's Costco position peaked at $436M in Q1 2026.
4,238 funds tracked by Wall St. Rank held Costco as of Q2 2026.

Based on Mariner's 13F filing for Q2 2026, filed 13 Aug 2026.