Clay, a Sales Tool for the A.I. Era, Raises $100 Million

Americans once made their own costumes and candy. Now, the holiday has rapidly commercialized, transforming into an economic juggernaut.

Investors cheered the Federal Reserve chair’s assessment. But some economists fear a case of déjà vu.

President Trump is locked in a showdown with the world’s richest man, who is far from a typical opponent.