Dalal Street extended the winning streak for an 8th consecutive session on September 12, with Nifty 50 comfortably closing above 25,100 for the first time since July 23, powered led by auto, pharma and metals names.

This also turned out to be the biggest weekly gain in nearly three months, as BSE Sesnex and Nifty gained 1.5 percent each.

At close, the Sensex was up 355.97 points or 0.44 percent at 81,904.70, and the Nifty 50 was up 108.50 points or 0.43 percent at 25,114.00. Broader indices underperformed the main indices with BSE Midcap and Smallcap indices closing with marginal gains. On the sectoral front, auto, pharma, metal, telecom added 0.5-1 percent, while realty, FMCG, media, PSU Bank ended lower.

Bharat Electronics, Bajaj Finance, Shriram Finance, Hindalco, Bajaj Finserv were among major gainers on the Nifty, while losers were HUL, Wipro, Trent, Eternal, Bajaj Auto.

In stock-specific action, Infosys shares jumped 1% on higher-than-expected share buyback of Rs 18,000 crore, Consolidated Construction shares surged 20% on orders win of Rs 180 crore, BSE shares rose 1.5% ahead of Sebi board meet outcome, JBM Auto's shares soared 14% on IFC's largest e-mobility investment worth $100 million, HFCL shares jumped 4% as Andhra government allotted 1,000 acres land to set up defence manufacturing facilities, Lupin shares rose 2.7% after Investec upgraded to 'buy' with a target of Rs 2,265.

More than 120 stocks touched their 52-week highs on the BSE, including GMDC, Bajaj Finance, Aditya Birla Capital, Anand Rathi, L&T Finance, Affle 3I, Zydus Wellness, Waaree Energies, among others. 

In an exchange filing released in the post market hours of September 11, Infosys announced that the share buyback program does not exceed 25 percent of the aggregate paid-up capital and accounts for 2.41 percent of the company. The buyback price has been set at Rs 1,800 per share. The record date for the latest buyback programme is yet to be announced. The company has said that the buyback will be done through the tender offer route.

Infosys' buyback price of Rs 1,800 apiece marks a premium of more than 19 percent from the stock's previous closing price of Rs 1,509.70 apiece. The stock gained more than 2 percent intraday after the announcement.