(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window.) * Exxon posts first annual loss as publicly listed company * Amazon, Alphabet among top boosts to S&P 500 * Indexes up: Dow 1.9%, S&P 500 1.8%, Nasdaq 1.8% (Updates to afternoon trading) Feb 2 (Reuters) - Major U.S. stock indexes were up more than 1% in Tuesday afternoon trading, helped by gains in Amazon.com and Google-parent Alphabet ahead of their results and by optimism over progress on a large fiscal pandemic relief package. Shares of Alphabet and Amazon.com Inc, both set to report their fourth-quarter earnings after market close, were among the top boosts to the S&P 500. ADVERTISEMENT Alphabet, which will report the cost and operating profit of its Google Cloud business for the first time, added 1.7%, while Amazon.com Inc rose 2.3%. Democrats in Congress prepared on Tuesday to take the first steps toward fast-track passage of President Joe Biden’s $1.9 trillion COVID-19 relief package. Adding to the upbeat mood, new cases of COVID-19 in the United States fell for a third week in a row, the first time since last September. “There’s been a back-and-forth emotional swing over the reality of problems we’re facing with COVID near term... and some form of the Biden proposal will pass, and there are certainly investors who are willing to look down the road and think the market and economy will look brighter,” said Rick Meckler, partner at Cherry Lane Investments, a family investment office in New Vernon, New Jersey. The recent mania driven by retail investors over heavily shorted assets showed some signs of fizzling out. GameStop Corp , one of the stocks that had run up sharply in the frenzy, was down more than 50%, falling sharply for the second day. The Dow Jones Industrial Average rose 586.99 points, or 1.94%, to 30,798.9, the S&P 500 gained 68.11 points, or 1.80%, to 3,841.97 and the Nasdaq Composite added 247.25 points, or 1.84%, to 13,650.65. ADVERTISEMENT Wall Street’s fear gauge, the Cboe Volatility index, retreated. Exxon Mobil Corp posted its first annual loss as a public company. However, its shares rose more than 1% as its quarterly adjusted profit topped estimates. Shares of United Parcel Service Inc gained after it beat quarterly profit estimates on a surge in home delivery volume due to pandemic-fueled online purchases of holiday gifts and staples. Advancing issues outnumbered declining ones on the NYSE by a 3.22-to-1 ratio; on Nasdaq, a 2.90-to-1 ratio favored advancers. The S&P 500 posted 16 new 52-week highs and no new lows; the Nasdaq Composite recorded 152 new highs and 7 new lows. (Additional reporting by Devik Jain and Medha Singh in Bengaluru; editing by Uttaresh.V, Maju Samuel and Dan Grebler) Our Standards: The Thomson Reuters Trust Principles.