Shares of Amazon, Nvidia and Tesla each dropped around 5% on Friday, as tech's megacaps lost $770 billion in market cap, following President Donald Trump's threats for increased tariffs on Chinese goods.

With tech's trillion-dollar companies occupying an increasingly large slice of the U.S. market, their declines sent the Nasdaq down 3.6% and the S&P 500 down 2.7%. For both indexes, it was the worst day since April, when Trump said he would slap "reciprocal" duties on U.S. trading partners.

After market close on Friday, Trump declared in a social media post that the U.S. would impose a 100% tariff on China and, on Nov. 1, it would apply export controls "on any and all critical software."

Amazon, Nvidia and Tesla all slipped about 2% in extended trading following the post.

The president's latest threats are disrupting, at least briefly, what had been a sustained rally in tech, built on hundreds of billions of dollars in planned spending on artificial intelligence infrastructure.

In late September, Nvidia, which makes graphics processing units for training AI models, became the first company to reach a market cap of $4.5 trillion. Nvidia alone saw its market capitalization decline by nearly $229 billion on Friday.

OpenAI counts on Nvidia's GPUs from a series of cloud suppliers, including Microsoft. OpenAI is only seeing rising demand.

In September it introduced the Sora 2 video creation app, and this week the company said the ChatGPT assistant now boasts over 800 million weekly users. Microsoft, which spends heavily on infrastructure to operate its cloud data centers, saw its market cap drop by $85 billion on Friday.

The sell-off wiped out Amazon's gains for the year. That stock is now down 2% so far in 2025. Amazon competes with Microsoft to rent out GPUs from its cloud data centers. The online retailer lost $121 billion in value during the day.

"There continues to be a lot of noise about the impact that tariffs will have on retail prices and consumption," Amazon CEO Andy Jassy told analysts in July. "Much of it thus far has been wrong and misreported. As we said before, it's impossible to know what will happen."

Tesla, which introduced lower-priced vehicles on Tuesday, saw its market capitalization sink by $71 billion.

The automaker reports third-quarter results on Oct. 22, with Microsoft earnings scheduled for the following week. Nvidia reports in November.

Google parent Alphabet and Facebook owner Meta fell 2% and almost 4%, respectively.

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