Anthropic Now Makes Its Own Spreadsheet Software. Here's What I'd Do With Microsoft Stock.

Anthropic, the artificial intelligence (AI) firm behind the Claude chatbot, now has a spreadsheet of its own. On Tuesday, Nov. 10, it released Claude Sheets and Claude Whiteboards in beta, and made its dashboard tool generally available under a new name, Claude Data.

This gives Claude an alternative to Excel. Microsoft (NASDAQ:MSFT) sells Excel as part of Microsoft 365, a business that pulled in about $111 billion in revenue for the software giant's fiscal 2026, which ended June 30. Microsoft shares dropped 2.2% on Tuesday, to roughly $533, but they're still up about 10% this year as I write.

I don't think a beta spreadsheet is a reason to sell the stock. But the launch is a good excuse to look at the business it overlaps with -- and one number in it that's been cooling.

Image source: The Motley Fool.

Claude Sheets: a companion to Excel, for now

According to Anthropic's launch post, Claude Sheets can make a spreadsheet with tabs, formulas, formatting, and drop-down menus, often from one prompt. Claude changes the cells directly, and colleagues can work on the same sheet together.

Anthropic is open about the limits, though. Its post says the sheets have "simple spreadsheet functionality" for now. And for anyone who needs everything Excel can do, it suggests exporting the file to .xlsx or CSV, or using Claude for Excel, which works in Microsoft's own spreadsheet.

The rollout to big companies is cautious, too. Sheets and Whiteboards are on by default for Team plans but off by default for Enterprise customers.

That might change as Anthropic adds features. But companies typically get Excel as part of Microsoft 365, a subscription that also includes email, Teams, file storage, and security tools. A better spreadsheet alone wouldn't replace all of that.

How much rides on Microsoft 365?

A lot.

Microsoft 365's commercial and consumer businesses brought in around a third of the $332 billion of revenue Microsoft reported for fiscal 2026.

Profit's tougher to nail down, because Microsoft now reports Microsoft 365 in a new agents and infra segment that also covers Azure, its cloud computing platform. Under the old setup, though, the productivity and business processes segment (Microsoft 365 plus LinkedIn and Dynamics) made $83.9 billion in operating income in fiscal 2026, up 20% from a year earlier. This was around 54% of the company's total, making it Microsoft's most profitable segment by a big margin.

And the business keeps growing fast. In the fiscal first quarter of 2027 (from July through September 2026), Microsoft 365 cloud revenue rose 17% year over year to $27.8 billion, or around 30% of total revenue. Microsoft 365 commercial cloud revenue also grew 17%, near the 16% to 20% pace it kept through fiscal 2026. Plus, management sees around 19% growth in constant currency (leaving out exchange-rate moves) this quarter, with growth picking up through the year.

Seat growth is cooling

The number to watch is seats. Growth in paid Microsoft 365 commercial seats was 6% to 7% year over year in each of the four quarters of fiscal 2026. In the fiscal first quarter, it slowed to 5%. In other words, more of Microsoft's growth is coming from charging each user more. Revenue per user climbed on upgrades to premium plans, such as Microsoft 365 Copilot (its AI assistant for work) and the E5 and E7 bundles.

CFO Amy Hood linked some of the seat slowdown to "weaker sales execution" in Microsoft's standard E3 plan and stand-alone products on the Oct. 28 earnings call. Notably, the quarter closed weeks before Claude Sheets arrived, so the release wasn't behind it.

Still, if a rival tool starts winning over Microsoft's customers, seat growth is likely where it'd turn up first.

Worth buying at $533?

Microsoft reported $18.04 per share over the past four quarters on a non-GAAP (adjusted) basis, excluding gains and losses from its OpenAI stake. At roughly $533, that's about 30 times adjusted earnings. Adjusted earnings per share climbed 18% year over year last quarter, so this isn't an excessively high price. But it doesn't leave much room for seat growth to keep sliding.

For investors who already hold Microsoft, I don't see a reason to sell over a spreadsheet that steers its heaviest users back to Excel. For new money, though, I think the stock's a little too pricey here.

Daniel Sparks and his clients do not have positions in any of the stocks mentioned. The Motley Fool has positions in and recommends Microsoft. The Motley Fool has a disclosure policy.