Investors became gloomy on Friday, threatening to derail a long winning streak for stocks, as inflation remained high.

US benchmark equity indexes were lower intraday amid declines in certain mega-cap stocks. The Nasdaq Composite was down 1.9% at 19,635.5 after midday Friday, while the S&P 500 fell 1.4% to 5,950.2.

Wall Street's holiday cheer ended abruptly on Friday, with all three main benchmarks slumping in a broad-based sell-off affecting even tech and growth stocks that had driven markets higher through ...