San Francisco – Nvidia, the world’s most valuable company, delivered another huge quarterly profit and a sales outlook that topped analyst estimates. It even announced a US$80 billion (S$102 billion) share buyback programme, but all this drew a lukewarm reaction from investors who sent its shares down.The AI chipmaker’s first-quarter profit hit US$58.3 billion (S$74.5 billion), up 211 per cent from a year ago and topping analyst expectations. Just three years ago, its quarterly profit was US$2 billion – about a 30th of what it is today.Sales in the current second quarter will be US$91 billion, compared with analyst average...