Taiwan Semiconductor Manufacturing has ridden to the rescue. The chip manufacturer's earnings, often seen as a bellwether for semiconductor demand, should reassure investors about the artificial-intelligence trade but it's a reminder of the U.S. technology sector's heavy reliance on the Taiwanese company.

TSMC's third-quarter profit crushed expectations while the company raised its revenue guidance for the year. That should be enough to reassure stockholders in Nvidia and other AI plays that there's no sign of a popping bubble yet.