A Chinese firm called DeepSeek managed to upend global markets at the start of the week, to drag down chipmaker Nvidia — and to surge to No. 1 in the iPhone app store, all in basically no time at all.Today, in this bonus episode, we talk through the news behind the freakout. How is a new A.I. model from one Chinese A.I. company making such a big splash? And what does it mean for the U.S. artificial intelligence industry? We want to hear from you. Email us at [email protected]. Find “Hard Fork” on YouTube and TikTok.. Unlock full access to New York Times podcasts and explore everything from politics to pop culture. Subscribe today at nytimes.com/podcasts or on Apple Podcasts and Spotify.