U.S. stocks rose Tuesday, signaling that major indexes may extend this week’s gains ahead of earnings from technology giants Amazon.com and Google parent Alphabet. The S&P 500 rose a day after the broad stocks gauge posted its biggest one-day advance since November. The Dow Jones Industrial Average gained 600 points, and the technology-heavy Nasdaq Composite Index climbed roughly 200 points Stock markets have steadied globally this week after a choppy January, when extreme moves in some individual stocks, signs of a slowdown in the U.S. economy, and concerns about the pace of the vaccine rollout and new coronavirus variants weighed on share prices. Investor sentiment has been lifted by robust earnings reports from large-cap companies, as well as a decline in coronavirus cases in the U.S. and several other major economies. Investors will parse quarterly earnings from Amazon.com and Alphabet after markets close. Shares of giant tech companies have continued to power the broader market in 2021, pushing the Nasdaq Composite up 4% so far this year. “The bar for tech was actually quite high” coming into earnings season, said Hani Redha, a multiasset portfolio manager at PineBridge Investments. “Overall, for the sector, we are still seeing very strong earnings delivered.” Earnings for the last quarter of 2020 have been better than analysts had anticipated. Of the 189 companies on the S&P 500 index that had reported results by late Monday, 81% have beaten expectations, according to FactSet. Some of the stocks that have been most popular among online day-traders plunged in premarket trading. Shares of GameStop continued to slump, dropping 40% ahead of the opening bell in New York. Headphones-maker Koss and AMC Entertainment Holdings each declined over 25%. Express, Naked Brand and BlackBerry also retreated. Investors are closely following discussions around another round of coronavirus relief in Washington. A group of Senate Republicans on Monday outlined their roughly $618 billion offer, including a round of $1,000 direct checks for many adults. The proposal omits measures favored by many Democrats, such as aid for state and local governments and a plan to raise the federal minimum wage to $15 an hour. “There is still hope of arriving at something bipartisan,” said Mr. Redha. Passing a smaller bill than President Biden’s proposed $1.9 trillion package along bipartisan lines could be positive for stocks by opening the way to more stimulus spending later in his term, Mr. Redha added.