⚠ The Multiple Assumes This Never StopsHigh threat

Costco's own 10-K contains a sentence most companies would never write: "We believe that the price of our stock currently reflects high market expectations for our future operating results."¹ It goes on to name what would break it — comparable sales growth, membership fee revenue including new sign-ups and renewal rates, gross margin, earnings, new warehouse openings, dividend or repurchase policy.

The numbers behind that warning: at $915.74 a share the company is worth about $406 billion, roughly 46 times trailing earnings and about 42 times forward, on 1.38 times sales and a 0.64% dividend yield². Trailing net income is $8.84 billion on $293.6 billion of revenue — a net margin of 3.0%.

There is a defensible case for a premium. Half the operating profit is a subscription with a 92% renewal rate; return on invested capital is 30.9% against a cost of capital nearer 7%³; the balance sheet holds $20 billion of net cash; and the earnings have compounded reliably for thirty years. A subscription business with those characteristics does not trade at a supermarket's multiple, and should not.

The case against is that the multiple has to be paid out of a very thin margin. Every 10 basis points of gross margin is about $270 million; every 10 basis points of SG&A is another $270 million. A company earning 3.0% of revenue has roughly a third of the buffer of one earning 10%, so the same operational wobble does three times the damage to earnings — and at 46 times, earnings damage is amplified again by the multiple.

The market has already shown what that looks like. Costco traded at 62.4 times earnings at its second fiscal quarter of 2025, with a market capitalisation of $475.8 billion⁴. It is now 46 times and $406 billion — a 15% fall in value across a period in which revenue grew 9.2% and net income grew 12.7%. The business did nothing wrong; the multiple simply came in.

What tests this threat is the gap between the earnings multiple and the earnings growth rate. Twelve percent growth at 46 times is a premium of roughly four times growth. History says the multiple compresses toward the growth rate over long periods, and Costco's own risk factor is a warning that the company knows it.