New Delhi, Nov. 22 -- A late-day unwind of AI euphoria erased early gains, Nvidia's post-earnings bounce faded as Bitcoin volatility spooked traders, even as Walmart's upbeat forecast and Google's resilience offered rare safe-haven lifts.

Wall Street's morning optimism gave way to a bruising reversal that exposed how fragile sentiment remains even after a stretch of blockbuster gains. The session began as a reaffirmation of the AI era: AI investment and datacenter demand were supposed to carry markets forward. Instead, profit-taking and a surge in crypto markets volatility combined to turn the tide, leaving the S&P 500 and Nasdaq to digest a sharp intraday loss.

The reversal centered on Nvidia. After an early jump on another strong quar...