Indian markets gained for the third consecutive session on Friday. The BSE Sensex ended at 49,206.47, up 256.71 points or 0.52%. The Nifty closed at 14,823.15, up 98.35 points or 0.67%. The markets posted weekly gains of over 1%. Analysts feel improvement in the domestic covid situation is critical for any sustainable up move else the rebound may again fizzle out in the following sessions.