Main Street Research LLC reduced its stake in Costco Wholesale Corporation (NASDAQ: COST) by a modest 1.7% in the fourth quarter of 2025, according to the firm’s most recent Form 13F disclosure filed with the Securities and Exchange Commission.
The Sausalito, California-based wealth management firm sold 1,093 shares during the period, leaving it with a remaining position of 62,366 shares in the membership warehouse retailer valued at approximately $53.78 million based on the closing price at the time of filing.
The trim is a minor adjustment rather than a strategic exit, with Main Street Research retaining a meaningful exposure to one of the most defensively positioned consumer franchises in the US equity market.
Costco is one of the firm’s five largest disclosed holdings alongside Nvidia, JPMorgan Chase, Procter and Gamble, and Palantir Technologies, reflecting the firm’s strategy of concentrating capital in high-quality businesses with durable competitive advantages.
Costco closed at $1,028.24 on May 22, 2026, giving the company a market capitalisation approaching $450 billion, and the stock has benefited from a period of sustained membership growth and strong comparable sales that have helped it outperform the broader S&P 500 over multiple time horizons.
The company is scheduled to report its fiscal third-quarter 2026 earnings on Thursday, May 28, with analysts focusing on membership renewal rates, same-store sales data, and any commentary on how the elevated gasoline prices generated by the Strait of Hormuz closure are affecting both consumer spending patterns and Costco’s own fuel revenues.
Costco’s business model, built around annual membership fees and bulk purchasing at thin margins, provides an unusually resilient revenue profile in inflationary environments, as members who have already paid for access tend to concentrate their discretionary spending at the retailer to extract maximum value.
UBS raised its price target on COST to $1,275 from $1,205 earlier in May, maintaining a buy rating and citing strong April net sales of $23.92 billion, a 13% year-on-year increase, as evidence of continued momentum heading into the fiscal third quarter.
The all-time closing high for COST of $1,094.32 was reached on May 19, 2026, putting the stock just below record territory as Main Street Research and other institutional holders assess whether the elevated valuation can be sustained ahead of Thursday’s results.
Institutional investors own approximately 69% of Costco’s outstanding shares, with the stock a core holding for a broad range of pension funds, endowments, and wealth management firms that view its combination of membership economics and consumer staples positioning as an ideal long-term compounder.
