BSE Sensex was trading flat at 52,739 levels, up 40 points, in the opening session on Friday. NSE Nifty50 was at 15,815 levels on the back of a 24 point rise. Tata Steel, Tech Mahindra, and HCL Tech were the top gainers, while Reliance Industries was the top loser on Sensex. As many as 192 companies, including JSW Energy and Finolex Industries, will release their quarterly earnings today.