Even though the shares of US car retailers rose this September, analysts predict that longer-term concerns over the threat of eccomerce and weak demand in the sector remain. O’Reilly Automotive rose on Monday, up 2.7 per cent to $215.15. It outperformed the broad S&P 500 index which weakened 0.2 per cent to 2,496. The Dow Jones Industrial Average also traded down 0.2 per cent at 22,296 on Monday in New York, while the Nasdaq Composite shed 0.9 per cent to 6,370. Genuine Parts, which distributes replacement car parts, saw the biggest gains of any stock in the S&P 500 on Monday, rising 6 per cent to $93.22 on news that it has agreed to buy Europe-based Alliance Automotive Group for $2bn. Used car retailer CarMax and auto parts retailers AutoZone and O’Reilly are up 10.6 per cent, 10.4 per cent and 9.7 per cent, respectively, for the month. The uptick comes following signs of improved trading for the sector. Earlier this month, AutoZone and CarMax both reported quarterly results that beat analyst estimates.