Nvidia's upbeat quarterly forecast signaled that the AI boom is not over, but it failed to bring buyers back into the "Magnificent Seven" stocks that have dipped in the last three months. The stock lost about 4 per cent to $125.81 in choppy trading, and other members of the group such as Microsoft and were lower on Thursday after Nvidia's earnings failed to inspire the kind of gains that became a hallmark of the AI rally through 2023 and 2024. Nvidia is viewed as a barometer of the health of AI