Main Street Research LLC reduced its position in Costco by 1.7% in the fourth quarter of 2025, selling 1,093 shares and leaving the firm with 62,366 shares, a stake valued at roughly $53.78 million in its SEC filing.
The move came as costco stock sat close to record territory ahead of the company's fiscal third-quarter earnings report scheduled for May 28. Costco reached an all-time closing high of $1,094.32 on May 19 and closed at $1,028.24 on May 22, by which point its market capitalisation was approaching $450 billion and institutional investors owned about 69% of outstanding shares.
The mood among sell-side analysts has been broadly positive: UBS raised its price target on Costco to $1,275 from $1,205 earlier in May and kept a buy rating, pointing to strong momentum. UBS cited robust April net sales of $23.92 billion — up 13% year over year — as evidence the company retains sales traction. UBS analysts wrote, "There's probably not a lot that can come from this print that will change the market's perception that [Costco] is a good place to be," and added, "Though, its superior position, levers, and capabilities to manage the upcoming headwinds will probably be more evident as the impact of tariffs become translucent in the coming months."
Costco entered the reporting window carrying the results of the quarter ended March 11: earnings per share of $4.58, beating the consensus estimate of $4.55 by $0.03, and quarterly revenue of $69.60 billion, up 9.2% from the prior year. The company paid a quarterly dividend of $1.47 on May 15, another signal of steady cash flow ahead of the May 28 release.
The selling by Main Street Research stands in contrast to several other institutional moves recorded for the same period. Mmbg Investment Advisors CO. boosted its holdings by 35.9% in the fourth quarter, buying 2,299 additional shares to finish with 8,708 shares. Brighton Jones LLC grew its stake by 12.3%, adding 2,172 shares to reach 19,825 shares, and Revolve Wealth Partners LLC increased its position by 13.1%, buying 130 shares to end with 1,123. Taken together, the activity underscores a mixed institutional picture: a modest trim from one holder amid fresh accumulation by others, while overall institutional ownership remains concentrated.
The tension for investors is clear. Shares are priced for resilience: a recent all-time high, a bullish UBS price target and April sales growth have already been baked into valuations. But the margin and guidance details in the May 28 report will be watched for signs that Costco can absorb or offset external pressures UBS alluded to — notably tariff-related headwinds — without derailing renewal rates and membership-driven cash flow.
The single question now sharpening the market is this: will the May 28 fiscal third-quarter print provide the concrete margin and guidance signals that justify the rally and UBS's $1,275 target, or will it show early evidence that the headwinds UBS warned about are beginning to bite? Investors will treat that answer as the decisive signal for the next leg of costco stock's move.
