MONTHLY BRIEF — OCTOBER 2026

Coffee with Walter

Good morning.

No rabbit holes. No 2,000-calorie answer when you wanted lunch. Just the facts.

This month, Walter opened a brand-new annual filing from a company millions of people know very well: Costco.

Everybody’s Talking About… Costco

Costco filed its fiscal 2026 10-K on October 7.

The company reported $303.2 billion in total revenue. But one number caught Walter’s eye: Costco collected about $5.9 billion in membership fees.

Costco finished the year with 84.1 million paid members. Renewal rates were 92.3% in the U.S. and Canada and 89.8% worldwide.

That’s a lot more than people buying giant jars of mayonnaise.

WHAT’S WORKING

Membership fee revenue rose 11% for the year. Costco says membership loyalty and high renewal rates are important to its profitability.

WHAT’S WEAK

Costco runs on thin retail margins. Its filing says controlling costs is critical, and even modest changes in expenses can have a significant effect on net income.

WHAT COULD BITE YOU

Costco specifically flags competition, tariffs and changing shopping habits as risks. It even notes that AI tools could change how consumers compare prices and shop.

Filing School

A 10-K isn’t just a pile of numbers.

The Risk Factors section is where a company tells investors—in its own words—what could go wrong.

Walter doesn’t predict what will happen.

He reads what the company already disclosed.

NEW ON WALTER’S DESK

Costco’s new annual filing is now on the desk, along with ongoing work on companies including Microsoft, Nvidia, Tesla, Amazon and Meta.

Straight from the filings. No guessing.

Around Walter10K

Behind the scenes, we’re testing the WALTER10K Case Console, checkout and report-delivery systems end to end.

We won’t call something live until it actually works.

P.S. from Whatson

84 million Costco members?

That’s a lot of people who could be throwing tennis balls instead.

🐾 Whatson