Stock Markets Tumble Amid Worries Over Tech Firms and Trade Tensions

A broad market sell-off hit Wall Street on Monday, with major stock indexes slumping more than 2 percent by the early afternoon as a recent blitz of bad news about technology companies and festering worries about a trade war between the United States and China continued to leave investors jittery.

Shares in major tech firms were among those hit hardest.

Amazon’s stock price was down 6 percent by midday after President Trump, who has repeatedly assailed the online retail giant over what he says is its abuse of the Postal Service and failure to pay adequate taxes, took another swipe at the company on Twitter.

Facebook, which has experienced a rash of defections by users since becoming embroiled in a scandal over data privacy last month, saw its shares drop more than 3 percent.

Shares of the electric carmaker Tesla slid about 8 percent after the company’s disclosure late Friday that its Autopilot system had been engaged in a Tesla vehicle involved in a fatal crash in California last month. The revelation came amid wider concerns about the company’s financial woes, which Elon Musk, Tesla’s chief executive, joked about on Twitter on Sunday. The stock’s performance on Monday suggested investors were not amused.

Manufacturing stocks also stumbled after China slapped tariffs of up to 25 percent on 128 American-made products in response to the Trump administration’s decision to place steep duties on imported steel and aluminum. Boeing was down 3 percent, Caterpillar fell 3.6 percent and 3M was off more than 4 percent.

With pork products among the goods subject to the Chinese tariffs, shares in Tyson Foods, a major American meat company, dropped 6.6 percent on Monday.