Apple Inc. sells a lot of smart watches during the holidays, but this year its sales of most Apple Watch models may well drop 100 percent — to literally zero — on Christmas Day.

That’s because of a ruling Thursday by the International Trade Commission that most Apple Watches contain parts that infringe on patents held by Masimo Corp., a producer of medical technology, and its sister company, Cercacor Laboratories Inc., both of Irvine, Calif. An import ban and a cease-and-desist order on sales both take effect on Dec. 25 — 60 days after the I.T.C. ruling — unless President Biden reverses the decision, which appears unlikely. (Presidents rarely overrule the independent, nonpartisan agency, which was founded in 1916 as the U.S. Tariff Commission.)

I’ve been talking to people from Masimo for months about the I.T.C. case and other cases they have going against Apple. I didn’t write anything because I wasn’t sure how strong Masimo’s arguments were. Now that it has scored this victory against Apple, the world’s most valuable company, I think it’s time to open the reporter’s notebook.

Masimo argues that Apple’s reputation for innovation is undeserved and that the company has made a practice of “efficient infringement” — using other companies’ technologies without permission and dealing with the legal fallout as necessary. The company points to something that Steve Jobs, Apple’s co-founder, said in 1996: “Picasso had a saying. He said, ‘Good artists copy; great artists steal.’ And we have, you know, always been shameless about stealing great ideas.”

Apple, of course, rejects this characterization and says the company respects other companies’ intellectual property. In Apple’s defense, it’s fair to assume that Jobs was speaking metaphorically, and not copping to a crime, when he said that the company stole.

On the other hand, Masimo has presented evidence that before launching Apple Watch models with competing technology, Apple hired the chief medical officer of Masimo and the chief technical officer of Cercacor, and then started looking “next level down.” Apple opened offices near Masimo’s and, according to Masimo, eventually hired more than 20 people from Masimo and Cercacor.

Let’s back up. Masimo, while not a household name, is a recognized world leader in patient-monitoring technologies