Concerns about the return on investment in AI intensified, causing the Nasdaq 100 index to fall 6.7% in October.

Tech giants' earnings reports failed to alleviate investor concerns about the return on investment in AI infrastructure, with the Nasdaq 100 index falling 6.7% in October, its worst monthly performance since March 2025. Amazon, Meta, and Alphabet all reported free cash flow deficits this quarter, with Amazon's deficit nearing $35 billion, while Microsoft's free cash flow was positive at $18.6 billion. Alphabet's free cash flow has been negative for two consecutive quarters, Meta's future spending commitments rose to $825 billion, and Alphabet's future spending obligations exceeded $1 trillion. ServiceNow, Twilio, and Fortinet saw their stock prices fall due to weaker-than-expected earnings guidance, with investors worried that products like Anthropic and OpenAI are eroding software companies' profit margins. (Source: Bloomberg)