Ambuja Cements jumped 4.67 per cent or Rs 9.80 to Rs 219.70 and was the top gainer on the Nifty at 10 am.
Nomura has upgraded the stock to buy from neutral.
It said current valuations are reasonable in context of net cash balance sheet and strong franchise.
The company would be a key beneficiary of pick up in non-south regions, it added.
The stock has 16 buy, 10 hold and 17 sell ratings, according to Eikon data.
Trades were at EV/EBITDA of 12.2x vs 10.8x of rivals, the data said.