The letter almost cost Nvidia $400 million. In late August, the U.S. Commerce Department sent a notice to the American chipmaker ordering it to halt sales of its most important chip, the A100, to Chinese customers. Overnight, hundreds of millions of dollars in potential sales that quarter looked as if they might evaporate. The company’s stock price fell 6 percent, and Nvidia warned the drop in sales could even slow down the development of its next generation chip, the H100.  Like almost every other American chipmaker today, Nvidia (pronounced “in-vi-dee-uh”) is heavily dependent on the Chinese market. In 2022, more than a fifth of Nvidia’s revenue came from China. The company’s concern about the letter underscored how U.S. efforts to hamstring China’s chip industry could backfire on its own domestic champions. The new requirements, Nvidia warned in its annual report, “may benefit certain of our competitors… and encourage customers in China to pursue alternatives