Mumbai, Dec. 31 -- The key equity barometers ended the last trading day of the year with substantial gains, as robust trading activity reflected optimism for the year ahead. The Nifty closed above 25,100, snapping a four-day losing streak, while the Sensex bounced back after five straight days of losses. Investors focused on the upcoming corporate earnings season.

Barring IT, all sectoral indices on the NSE ended in the green, led by gains in oil & gas, consumer durables and metal stocks.

As per provisional closing data, the barometer index, the S&P BSE Sensex advanced 545.52 points or 0.64% to 85,220.60. The Nifty 50 index gained 190.75 points or 0.74% to 26,129.60.

The broader market outperformed the frontline indices. The S&P BSE M...