Mumbai, Feb. 1 -- The key equity indices tumbled during the ongoing Budget 2026 proceedings. Investor sentiment weakened after the government announced an increase in the securities transaction tax (STT) on futures contracts to 0.05%. Nifty skid below 25,000 level, breaching its 200-day moving average.

Oil & gas shares plunged for the second consecutive trading session.

At 12:50 IST, the barometer index, the S&P BSE Sensex declined 994.52 points or 1.13% to 81,338.35. The Nifty 50 index tumbled 278.45 points or 1.09% to 24,994.

In the broader market, the BSE 150 Mid-Cap index declined 1.54% and the BSE 250 Small-Cap index tumbled 1.12%.

The market breadth was weak. On the BSE, 1,711 shares rose and 2,215 shares fell. A total of 217 sh...