A key tech-stock volatility metric options traders have been watching all year is reversing, sending a sign to investors that the U.S. bond market may now be usurping AI optimism as the primary driver of the stock market.The spread between the volatility of big tech names and the rest of the stock market – measured most frequently by the difference between the Cboe's VIXEQ and VIX indexes – blew out to record highs this summer as tech giants behind the