Mariner
COST icon

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
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
Invesco
Invesco Atlanta, Georgia $1.02T AUM 30.18% 1-Year Est. Return
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.66T AUM 25.57% 1-Year Est. Return
Bank of America
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
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

Mariner's COST Position: Q1 2026 in Review

Mariner increased its Costco (COST) stake by 10% in Q1 2026, buying an estimated $39.7M and bringing the position to 437,088 shares worth $436M. The position accounts for 0.51% of the portfolio, ranked #36.

Mariner first reported a position in COST in Q2 2013 and has held it in 52 quarters since. 4,236 funds tracked by Wall St. Rank hold COST as of Q1 2026.

  • Mariner held 437,088 shares of Costco worth $436M as of Q1 2026.
  • Mariner bought 40,755 Costco shares in Q1 2026, an estimated $39.7M.
  • Costco made up 0.51% of Mariner's portfolio in Q1 2026, its #36 holding.
  • Mariner first reported a position in Costco in Q2 2013 and has held it in 52 quarters since.
  • 4,236 funds tracked by Wall St. Rank held Costco as of Q1 2026.

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