Stock Market News: The headline indices closed in the red for the second day on July 18. Sensex index closed at 81,757.73 down by 501.51 points or 0.61 per cent. On the other hand the Nifty 50 finished in the red down by 143.05 points or 0.57 per cent at 24,968.4. The declines in the market came amid uncertainty regarding the signing of a trade deal between India and the US.