Nvidia shares' 9% recovery Tuesday was the second-best day in terms of market cap added for any company ever, trailing only a record it set in July.

Nvidia Corp., the poster child of the AI frenzy, sank 17 per cent and headed toward the biggest market-cap loss for a single stock in market history. The AI leader wiped of $500 billion of its market value and shed 21 per cent off its stock price in two days.