You may not have noticed -- it's not getting a lot of attention -- but the last few days, the tech-heavy Nasdaq stock exchange has been in kind of a funk.

Since hitting its all-time closing high of 20,056 back on Feb. 19, the tech-heavy stock index has fallen an unlucky 13%, closing Monday at 17,453. Stocks of all stripes have gotten hit, including one market giant whose fall I bet almost nobody saw coming:

Microsoft (MSFT -3.34%) is down 8.7%. That's not as much as the rest of the Naz. But it's a big enough fall to push Microsoft stock down to a 52-week low.

"It's time to sell Microsoft," said absolutely no one

Is there a good reason for investors to be selling Microsoft right now? If there is, it's escaped Wall Street's notice.

Microsoft touched its most recent high on Feb. 20, a day after the rest of the market began sinking. And it did so at the same time as the company announced a game-changing "Majorana 1" quantum computing chip built upon what it called a new type of matter. Not solid. Not liquid. Not gas. But something... else. Whatever it is, Microsoft says it might be able to use it to put as many as one million qubits on a quantum chip.

(That's a lot of qubits. Alphabet's (GOOG -4.41%) (GOOGL -4.49%) experimental Willow quantum chip is said to have only 105 qubits).

Wall Street loved the news. Since it broke, UBS and Goldman Sachs have both doubled down on their "buy" ratings on Microsoft stock. Bernstein argued that Microsoft is ahead of "everyone else." About the only bad news the company has put out over the past month was the announcement that it's canceled some data center leases. Even that bad news isn't necessarily all bad if it means that Microsoft will be saving money by not leasing more artificial intelligence (AI) computing capacity than it actually needs.

Image source: Microsoft.

Office + Azure = 75% of Microsoft

As fascinating and unexpected as Microsoft's quantum news was, the rest of the company is still rolling along just fine without it. As recently as 2023, we clocked Microsoft getting 60% of its revenue from just two sources: "server products and cloud services" (i.e., Azure) and "office products and cloud services" (Office, in other words).

But that was then, and this is now. As the artificial intelligence revolution accelerated, Microsoft's Azure business has boomed. At last report, S&P Global Market Intelligence data showed "Intelligent Cloud" making up an astounding 43% of Microsoft's annual revenue. And "productivity and business processes," which basically means Office (plus SharePoint, Teams, and a few others), accounts for another 32% of the business.

Put them together, and that means Microsoft gets 75% of its revenue from these two sources, which are high-margin sources, too. Combined, they account for more than 82% of the company's operating profit, roughly $90.1 billion in profit on $183.1 billion in revenue. That's an astounding 49.2% operating profit margin, meaning for every $1 Microsoft makes from these two businesses, it keeps $0.49 (before taxes) as profit.

(The remaining 25% or so of Microsoft's business is no slouch, either. Although slightly less profitable, they only bring the entire company's operating margin down to about 45%).

Image source: Getty Images.

Does Microsoft stock deserve to be trading at a 52-week low?

All of this is to say that Microsoft stock is doing just fine. Nothing has changed in the less-than-a-month since the company announced its quantum news to explain why the stock deserves to be suddenly trading at a 52-week low.

No, that even includes President Trump's tariffs tirade. Granted, Microsoft carries some risks from a trade war. It imports a lot of computer chips from Taiwan, for example, and I'd say the risk that the President will continue hiking tariffs to include Taiwan among his targets to encourage more semiconductor production in the U.S. is relatively high. Still, when your operating profit margin is 49%, you can probably afford to pay a bit of tariff and continue chugging along relatively unscathed.

There's also the risk that other countries, hit with Trump tariffs, will hit back with tariffs of their own and other non-tariff trade barriers that might affect Microsoft's business. That said, the simple fact is that tariffs have a much bigger impact on companies trading in easily tariffed physical goods than on tech stocks like Microsoft, whose stock in trade consists primarily of electronic ones and zeros.

At 30 times earnings, I won't say Microsoft is the cheapest stock on the planet. It actually costs a bit more than the average S&P 500 stock, which trades at 28x earnings. But if you liked Microsoft stock a month ago, I don't see much that has changed over the past few weeks that should make you like this stock any less today. And it's more affordable now.