Bulls held sway on the Street for yet another session on Monday helped by banks and financial stocks. Individually, HDFC Bank, Reliance Industries (RIL) and Infosys were top contributors. It was the fifth straight gain for the domestic stock markets. The BSE Sensex surged by 855.30 points or 1.09% to 79,408.50, while the Nifty gained 273.90 points or 1.15% to end the day at 24,125.55.Commenting on the day's action, Rupak De, Senior Technical Analyst at LKP Securities said that Nifty has given a clean breakout above the previous swing high on the daily chart as optimism among investors increases. Sentiment is expected to remain positive as long as the index sustains above the critical moving average, said De.