Nasdaq falls 1.67% as tech sell-off intensifies ahead of Amazon earnings

Selling concentrated in large-cap tech. Alphabet -12.95% on earnings miss and AI spending concerns. Microsoft -1.04% despite Azure beat as capex plans draw scrutiny. Caterpillar -9.01% on unchanged outlook and tariff costs. Merck +4.39% on beat and raise. Amazon -3.83% ahead of after-close report; focus on AWS growth, cloud margins, and returns on $220B capex plan.