Investors pummeled technology company stocks on Tuesday, prolonging a bearish streak that is now two months old.
Enthusiasm for the tech sector has propeled stock markets ever higher for some time. But the intensifying scrutiny of the industry — and the prospect that it could face new regulations — has taken the sheen off, and investors are rushing to sell shares of companies that could be vulnerable to being reined in by the authorities.
After spending the morning in positive territory, stocks began to slip broadly in the early afternoon, with once high-flying tech shares weighed down by a series of negative reports.
Nvidia, a chip maker that has made supplying chips to self-driving vehicles a major part of its growth strategy, said it was suspending tests worldwide after an autonomous Uber vehicle struck and killed a pedestrian in Tempe, Ariz., last week. Nvidia shares plunged 7.8 percent on Tuesday, the sharpest decline of any company in the Standard & Poor’s 500-stock index.
Shares of Tesla, a maker of electric-powered vehicles that trades on the tech-heavy Nasdaq composite, fell more than 8 percent. The National Transportation Safety Board said on Tuesday that it was opening an investigation into a fatal crash involving a Tesla vehicle in California last week. The safety board said it was unclear whether an automated driving system was operating at the time of the crash.
Recent concerns about the autonomous driving industry are adding to broader worries about the potential for increased regulation of tech firms. Facebook stock fell 4.9 percent Tuesday amid reports that Mark Zuckerberg, the company’s chief executive, would testify before Congress about the way the firm manages user data.