Shares in industrial companies, viewed as particularly vulnerable to rising trade tensions with China, have dropped more than 10 percent since September. Economically sensitive financial stocks have slid 7.5 percent. Shares of homebuilders, which are vulnerable to rising rates, have fallen more than 30 percent.

The potential for higher borrowing costs is also weighing on smaller companies that often borrow money by issuing floating rate debt, which can become more difficult to pay off as interest rates rise. The Russell 2000 index of small capitalization stocks is down 14 percent from its high.

“This is simply a continuation of the recent repricing of risk, or growth scare, that we’ve basically been seeing since the end of September,” said Talley Leger, an equity strategist with Oppenheimer Funds.

When the stock market hit its peak in September, technology had led the way, accounting for 50 percent of the gains for the year. The tech giants, at first, seemed immune to the sell-off that followed on broader economic worries.

Not anymore. Through Friday, roughly a quarter of the market’s decline since September was because of Amazon, Apple, Facebook and Alphabet, according to data collected by S&P Capital IQ. The sharp sell-off on Monday will only add to that tally.

Investors appear especially focused on any signs that extraordinary profits generated by these giant tech companies are under threat.

The specter of regulation is looming over the shares of Facebook, as it deals with the fallout and costs from a data breach, privacy lapses and management missteps. The pressure has only been amplified by renewed scrutiny over its response to Russian efforts to use it to influence the 2016 presidential election. The stock dropped another 5.7 percent on Monday.