AI stocks just lost $5 trillion — but history says the stock market's sweetest stretch starts now

The AI trade just had its scariest October in years. The rest of the stock market barely noticed. The biggest AI and chip stocks have shed about $5 trillion in market value since Oct. 6, by Yahoo Finance calculations. Nvidia (NVDA) and Alphabet (GOOGL) have each given up roughly $835 billion in market cap, and Intel (INTC) lost nearly half its value in October. Everything else? The other 625 large US stocks in that tally added about $1.3 trillion. And while the S&P 500 (^GSPC) slipped this week, 9 of its 11 sectors rose about 1% or more, something that hadn't happened in any week since at least 1999, by Yahoo Finance calculations. Yahoo Finance Jeff Hirsch, editor of the Stock Trader's Almanac, has a name for this: "Octoberphobia.