Tech sell-off drives US markets down by nearly $1tn after subpar earnings reports

AI builders are getting a reminder that investor patience has limits: US technology stocks shed nearly $1tn in value from the Nasdaq in one week, extending the index's one-month loss to about $2tn. The sell-off accelerated after disappointing earnings from major tech companies, as markets questioned how quickly heavy spending on AI infrastructure and model development will translate into durable revenue and profits. The S&P 500 fell more than 1% on Friday and was close to erasing its October gain, despite reaching an all-time high during the month. For practitioners, the near-term effect may be tighter scrutiny of AI budgets rather than an immediate pullback. Cloud providers and model vendors will face more pressure to prove use, margins and customer value, while enterprise teams should expect procurement decisions to focus less on experimentation and more on measurable cost savings or revenue.