THe BSE benchmark Sensex was trading up 314 points from the day's opening to enter the 18,000 zone at 18,042, near its intra-day high level.
The Nifty hovered around 5,310 up 84 points from its previous close.
Gainers on the index were Tata Motors up 6%t at Rs 1,622 and Jindal Steel at Rs 642, both up 4%.
The auto index was replaced by the Capital goods index as the top sectoral performer up 3.2% at 13,040, while the Auto index was up 3% at 8,745, followed by the Metal index up 2.8% at 15,703.
The oil & Gas index was the laggard in trade down 0.3% at 9,212.
Strong buying in the mid-cap and small-cap space saw the respective indices outperform the benchmark, as the Mid-cap index gained 2.5% at 6,638, and the Small-cap notched up 3.3% at 8,063.
Stocks leading the Mid-cap pack were Manappuram General Finance at Rs 103 up 125, followed by Parsvnath Developers at Rs 29 up 10% and Sanwaria Agro at Rs 140 up 9%.
In the small-cap space, Nitesh Estates neared its upper circuit at Rs 25, followed by shree Ram Mills at Rs 139 both up 18%, and Geodesic at Rs 87 up 17%.