Stocks Extend Declines, Led Lower by Tech Shares

U.S. stocks tumbled Thursday as a wave of selling spread beyond the technology sector, taking down swaths of the market.
The Dow Jones Industrial Average dropped around 300 points, or 1%, after closing Wednesday at an all-time high. The S&P 500 shed 1.4%, and the Nasdaq Composite lost 2%.
Stocks’ momentum has faltered the past week as investors have faced a sharp and swift rise in bond yields. Money managers have broadly attributed the shift to bets on the economy picking up, something that should be a boon to corporate profits. But the swiftness with which yields have moved has also had another effect: It has tempered enthusiasm for more richly valued, risky parts of the market.
Investors rushed out of some of the hottest stocks of the year, sending shares of companies…