Semiconductor shares in the S&P 500 Index plunged more than 5 percent, the most in two years, after a report that Apple Inc. plans to start using its chips as soon as 2020 rather than processors made by from Intel Corp. All 15 members of the group lost at least 3 percent, with Intel down 7.7 percent, its biggest rout since January 2016.

The group was already lower by 3 percent before the Bloomberg News report, as a renewed tumble in technology shares led broader market measures to the worst day since the early February selloff. Chipmakers, which set a record just three weeks ago, have now lost 12 percent amid an exodus of cash from a popular semiconductors exchange-traded fund last month.

“This is part of the tech unwind story that was exacerbated with Apple Inc.’s move toward eliminating parts of the food chain in favor of doing it themselves,” said Josh Lukeman, head of ETF market making for the Americas at Credit Suisse AG.

Investors pulled almost a half a billion dollars — the most on record — from the VanEck Vectors Semiconductors fund in March. The fund, which goes by the ticker SMH, had attracted record inflows a month earlier.

While Intel pushed the group deeper into the red, there were other signs of trouble in a group that had rallied more than 50 percent in the prior two years.

Nvidia Corp., the ETF’s fifth largest holding at 5.1 percent, is down almost 9 percent in two weeks. It more than tripled in 2016 and doubled again last year. Micron Technology Inc., another sector heavyweight, has lost 18 percent since March 20, after it gave a disappointing sales forecast for third-quarter. Its dizzying pace of revenue growth had fueled its rally.