Sensex up by 620 pts to open at 55,505; Nifty begins session at 16,527

Markets opened in the green on Monday as Sensex gained 620 pts to open at 55,505. Nifty begins session at 16,527.Markets opened in the green on Monday as Sensex gained 620 pts to open at 55,505. Nifty begins session at 16,527.