Mumbai, Jan. 29 -- The key equity benchmarks ended with substantial gains on Wednesday, rising for the second consecutive session as investors kept an eye on the US Federal Reserve's interest rate decision later today and the Union Budget this weekend. The Nifty ended above the 23,150 mark.

The S&P BSE Sensex rallied 631.55 points or 0.83% to 76,532.96. The Nifty 50 index advanced 205.85 points or 0.90% to 23,163.10.

The broader market outperformed the frontline indices. The S&P BSE Mid-Cap index added 2.54% and the S&P BSE Small-Cap index rallied 3.28%.

The market breadth was strong. On the BSE, 2,979 shares rose and 1,009 shares fell. A total of 94 shares were unchanged.

The NSE's India VIX, a gauge of the market's expectation of vo...