U.S. markets sank Tuesday, with the blue-chip Dow Jones industrial average sliding 832 points, as a selloff in the technology sector exacerbated concern over rising interest rates and heightened trade tensions.

The 30-member Dow Jones fell 3.2 percent to 25,598, well below a January high reached before President Trump imposed an array of tariffs that corporate America fears will bite into profit margins. The broader S&P 500 tumbled 3.3 percent and the tech-heavy Nasdaq fell 4.1 percent.

Alphabet, parent company of search-engine provider Google, dropped 5.1 percent to $1,081 in New York trading as the firm grappled with the disclosure of a bug that exposed personal data of as many as 500,000 users — several months after the Mountain View, Calif.-based company discovered it.

That heightened federal scrutiny of how American businesses gather, protect and use consumer data and may push Congress toward passing a federal privacy law. Such worries are aggravating the effects of worries that Trump's tariffs on $250 billion of Chinese imports will hurt U.S. tech companies.

The White House has also placed duties on steel and aluminum and is considering 25 percent levies on shipments of cars and car parts. Though large corporations have largely escaped damage so far, retailers and manufacturers have warned that may change by the end of this year.

Winona, Minn.-based Fastenal, whose gross profit margin tightened 100 basis points in the three months through September, illustrates the potential challenges.

While early rounds of China tariffs, affecting $34 billion and $16 billion of goods, respectively, had little impact on Fastenal, the last round covering $200 billion of imports was another matter.

That's "directly impacting the North American supply chain for our customers," Chief Executive Officer Daniel Florness told investors on an earnings call Wednesday. Duties have now been applied to about half of the products China ships to the U.S., and that ratio isn't "too far off the mark of what we're seeing in our business," he said.

Among the reasons for mounting concern over tariffs, despite minor economic harm so far, "is that the net costs obscure concentrated losses," said Michael Gapen, an economist with British lender Barclays Plc. "Tariffs act as a tax on consumption, with losses born primarily by consumers."

Businesses facing a potential drop in demand as they raise prices to compensate for the duties are, at the same time, contending with rising interest rates that will make debt repayment more expensive. The Federal Reserve has raised interest rates three times this year alone, to a range of 2 percent to 2.25 percent, and economists expect another 25 basis-point increase before Dec. 31.

The Fed "has gone crazy," Trump, who has previously expressed his disapproval of higher rates, told reporters before a rally in Erie, Pa.

But with broad economic growth coupled with a sliding unemployment rate, the Fed's monetary policy committee has little choice but to raise interest rates, said Greg McBride, chief financial analyst for Bankrate.com.

"We're at an inflection point," he told the Washington Examiner. "Those higher rates become a headwind to the market, and they also make other investment options more attractive relative to stocks, which have been the only game in town."