July 20 (Reuters) - Wall Street"s main indexes jumped on Tuesday, as economically sensitive stocks staged a comeback after a sharp selloff in the previous session, while International Business Machines (IBM) gained on strong second-quarter results. All the 11 S&P 500 sectors indexes advanced, with energy (.SPNY), financials (.SPSY) and industrials (.SPLRCI) rising more than 2% each. The move was a sharp reversal from Monday"s trading session where the blue-chip Dow Jones index (.DJI) logged its worst day in nearly nine months on concerns that a surge in Delta variant infections might lead to renewed COVID-19 shutdowns and a protracted economic recovery. "There should be a normal natural pullback in the market. So we needed a trigger and it was the Delta variant, and it made everyone pause," said Eric Diton, president and managing director of the Wealth Alliance in New York. "This could be a reflex rally, we might have more of a sell-off, but at the end of the day, nothing has really changed. If the Delta variant wreaks havoc, that doesn"t mean we"re not going to have an economic recovery. Perhaps, it is not as strong, it"s just delayed." Meanwhile, the second-quarter earnings season began on a strong note, with 91.1% of the 56 S&P 500 companies reporting profits above estimates, as per IBES Refinitiv data. Analysts now expect year-on-year S&P 500 earnings growth of 72.9% for the April-June period. Shares of IBM (IBM.N) climbed 3.5% and was the top gainer on the Dow as brokerages raised their price targets on the stock following robust growth in the blue-chip technology firm"s cloud and consulting businesses. read more HCA Healthcare Inc (HCA.N) surged 14.1% and was the top percentage gainer on the S&P 500 index after the hospital operator raised its 2021 earnings forecast for the second time, as patient volumes recover. Focus is now on earnings reports from companies such as Netflix Inc (.NFLX.O) and Chipotle Mexican Grill (CMG.N) due later in the day. At 11:55 a.m. ET, the Dow Jones Industrial Average (.DJI) was up 583.37 points, or 1.72%, at 34,545.41 and the S&P 500 (.SPX), set to snap a three-day losing streak, was up 62.91 points, or 1.48%, at 4,321.40. The Nasdaq Composite (.IXIC)was up 195.97 points, or 1.37%, at 14,470.96. The indexwas on track to break a five-day losing streak. Halliburton Co (HAL.N) rose 4.9% after it posted a second-straight quarterly profit, as a rebound in crude prices from pandemic lows buoyed demand for oilfield services. read more McKesson Corp (MCK.N), Cardinal Health Inc (CAH.N) and AmerisourceBergen Corp (ABC.N) jumped between 3.7% and 4.8%. The three drug distributors agreed mid-trial to pay up to $1.18 billion to settle claims by New York state and two of its biggest counties over their role in the nationwide opioid epidemic. read more Advancing issues outnumbered decliners by a 5.15-to-1 ratio on the NYSE and by a 3.48-to-1 ratio on the Nasdaq. The S&P index recorded 32 new 52-week highs and no new low, while the Nasdaq recorded 34 new highs and 63 new lows.