A few days after a lawyer used ChatGPT to write a brief filled with made-up cases, a group of A.I. experts released a letter warning of the “risk of extinction” from the technology. But will A.I. ever be good enough to pose such a threat? Then, FAANG is now MAAAN, with the addition of Nvidia. Here’s how the GPU company became a trillion-dollar behemoth. Plus: Kevin, Casey and the New York Times tech reporter Kate Conger answer Hard Questions from listeners.