SEC 13F Intelligence

Mainstream Capital Management LLC / COST

Mainstream Capital Management LLC’s Costco Wholesale Corporation Position

Does Mainstream Capital Management LLC own Costco Wholesale Corporation (COST)? Yes — 2.3K shares worth $2M (+1.56% of its 13F portfolio) as of Q1 2026, up from 2.3K shares the prior filed quarter.

Position Value
$2M
Q1 2026
Shares
2.3K
% of Portfolio
+1.56%
Quarters Held
7
currently held

Position History COST

Reported value by quarter
Q3 ’24: $2MQ3 ’24Q4 ’24: $2MQ4 ’24Q1 ’25: $2MQ1 ’25Q2 ’25: $2MQ2 ’25Q3 ’25: $2MQ3 ’25Q4 ’25: $2MQ4 ’25Q1 ’26: $2MQ1 ’26filingsflow.com
QuarterSharesValue% of Portfolio
Q1 20262.3K$2M+1.56%
Q4 20252.3K$2M+1.31%
Q3 20252.4K$2M+1.47%
Q2 20252.3K$2M+1.64%
Q1 20252.3K$2M+1.71%
Q4 20242.2K$2M+1.40%
Q3 20242.2K$2M+1.63%

Common-stock position only; options are excluded. Quarters where the fund filed no 13F or reported no position are absent. See Mainstream Capital Management LLC’s full portfolio or all institutional holders of COST.