Stocks fell as earnings from megacap companies failed to reassure investors about the durability of the rebound in the artificial intelligence trade this week. Crude oil climbed after tensions flared in the Middle East. Asian shares fell 0.8%, with the Kospi Index — a barometer for the AI trade — declining 1.8%, and chip heavyweights Samsung Electronics Co. and SK Hynix Inc. in the red. Contracts for the Nasdaq 100 Index slipped 0.9% and those for the S&P 500 dropped 0.5% following a split set of results from Tesla Inc. and Meta Platforms Inc.