To say that the highly anticipated presentation by NVDA CEO Jensen Huang had a market impact, would be an understatment: not only did Huang's comments spark a $250 billion surge in NVDA's market cap, he also managed to turn around a nearly 2% drop in the S&P and make it into a 1% gain...
... he also transformed the Nasdaq's early 1% slide in the the S&P and made it into a 2% bounce, something which as the next chart shows, happens only at very "special" times for the market.