(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window.) * Energy sector down after hitting highest since Jan 2020 * Big banks set to start reporting results from Wednesday * Indexes up: Dow 0.4%, S&P 0.3%, Nasdaq 0.1% (New throughout, updates prices, market activity and comments to late afternoon; changes byline and adds NEW YORK dateline) NEW YORK, Oct 11 (Reuters) - U.S. stocks were mostly lower in afternoon trading Monday with trading choppy as investors were cautious before third-quarter earnings season. Indexes reversed earlier gains, with the Dow and S&P 500 lower and the Nasdaq essentially flat. Supply chain problems and higher costs for energy and other things have fueled concern about earnings, set to kick off with JPMorgan Chase & Co results on Wednesday. JPMorgan shares were down 1.9%, among the biggest drags on the S&P 500, and the S&P financial index was down 0.7%. “I was surprised to see the market up this morning because earnings season is right ahead of us, and the market is a bit cautious going into this earnings season,” said Tim Ghriskey, chief investment strategist at Inverness Counsel in New York, New York. “Supply chain issues may have impacted earnings for a number of companies and certain industries more than others.” The Dow Jones Industrial Average fell 131.61 points, or 0.38%, to 34,614.64, the S&P 500 lost 12.64 points, or 0.29%, to 4,378.7 and the Nasdaq Composite dropped 8.08 points, or 0.06%, to 14,571.46. Analysts expect a 29.6% year-over-year increase in profit for S&P 500 companies in the third quarter, according to IBES data from Refinitiv as of Friday, down from 96.3% growth in the second quarter. Energy was also lower after hitting its highest since January 2020. Higher oil prices have fed into concerns about rising costs for businesses and consumers. Market participants said traders may have been out for the U.S. Columbus Day holiday. U.S. bond markets shut Monday for the holiday. Among individual stocks, Southwest Airlines Co slipped 3.2% on a report that it canceled at least 30% of its scheduled flights on Sunday. Advancing issues outnumbered declining ones on the NYSE by a 1.08-to-1 ratio; on Nasdaq, a 1.08-to-1 ratio favored decliners. The S&P 500 posted 40 new 52-week highs and 7 new lows; the Nasdaq Composite recorded 83 new highs and 109 new lows. Additional reporting by Shreyashi Sanyal and Devik Jain in Bengaluru; Editing by Arun Koyyur, Aditya Soni and David Gregorio Our Standards: The Thomson Reuters Trust Principles.