Sometimes the little guy wins. Well, "little" is relative—Masimo is a publicly traded medical technology company—but when you're going up against Apple, pretty much everyone looks small. On Friday, a federal jury in California decided that Apple infringed a patent held by Masimo Corporation (MASI) covering blood-oxygen reading technology, and now the iPhone maker owes $634 million for its trouble.

Masimo Claims Victory

Masimo, which specializes in medical-monitoring technology, didn't hold back in celebrating the verdict. The company released a statement calling it "a significant win in our ongoing efforts to protect our innovations and intellectual property." That's corporate-speak for: we told you so, and now there's a price tag attached.

A Multi-Year Battle Over Your Wrist

This legal fight has been brewing since 2023, and it's already had real-world consequences for Apple Watch buyers. The dispute centers on blood-oxygen sensors—those little lights on the back of your Apple Watch that measure your SpO2 levels.

Back in January 2024, Apple took the unusual step of removing the blood-oxygen feature entirely from U.S. versions of the Apple Watch Series 9 and Ultra 2. Why? To sidestep a potential sales ban. The International Trade Commission had ruled that Apple's sensors infringed patents owned by Masimo. Rather than pull the watches from shelves completely, Apple offered modified versions that could keep selling without interruption.

But the story didn't end there. By August, Apple reintroduced the blood-oxygen monitoring feature after U.S. Customs and Border Protection gave the green light for imports of the devices. Masimo promptly challenged that decision in court, pointing back to the 2023 patent infringement case that led to the feature being disabled in the first place.

The Scoreboard

So where does this leave investors? On a year-to-date basis, Apple stock has climbed 11.71%, according to market data. Meanwhile, Masimo stock has fallen 10.35% during the same period. The $634 million verdict might help change that narrative for Masimo shareholders, though for a company of Apple's size, it's more of a sting than a body blow.

According to stock rankings, Apple maintains a growth score of 96.81% and a momentum rating of 77.08%, suggesting the patent dispute hasn't significantly dented investor confidence in the tech giant. Still, $634 million is real money, and this case serves as a reminder that even the biggest companies can't just borrow other people's innovations without consequences.