Mumbai, Aug. 19 -- The domestic equity indices traded with substantial gains in the early afternoon trade, buoyed by investor optimism surrounding potential GST reforms and positive developments in the Russia-Ukraine peace negotiations.

The Nifty traded above the 25,000 level. Media shares advanced after declining in the past two consecutive trading sessions.

At 12:30 ST, the barometer index, the S&P BSE Sensex, jumped 452.55 points or 0.56% to 81,720.18. The Nifty 50 index advanced 124.25 points or 0.50% to 25,001.45.

In the broader market, the S&P BSE Mid-Cap index added 0.54% and the S&P BSE Small-Cap index rose 0.75%.

The market breadth was strong. On the BSE, 2,496 shares rose and 1,409 shares fell. A total of 183 shares were unc...