MUMBAI: If Infosys' stock price is anything to go by, shareholders are willing to give the returning founder NR Narayana Murthy the benefit of doubt. Infosys shares have appreciated nearly 50% since June 1, the day of Murthy's appointment, to hit their lifetime high of Rs 3,483 on Tuesday, adding nearly Rs 64,000 crore to the company's market capitalisation at Rs 1.98 lakh crore.Meanwhile, a slew of brokerages, including JPMorgan, Nomura, Barclays, BNP Paribas and others, have upgraded the stock over the past few weeks. The number of 'buy' ratings on the stock has climbed to its highest level in past 20 months.About 61% analysts have 'buy' recommendations on the stock compared with only 13% 'sell' calls."We have 'buy' rating on Infosys with a price target of Rs 4,000.""We have 'buy' rating on Infosys with a price target of Rs4,000. We raised FY15 and FY16 revenue estimates by 3% on a cost optimisation drive by the company and better revenue growth prospects. Anecdotal evidence suggests there is uptick in large deal participation and win rates by Infosys," said Mitali Ghosh, research analyst at DSP Merrill Lynch, in a note."We also believe smooth CEO succession, which is due early 2015, is top priority for Chairman Narayana Murthy. External candidates are also being identified for the post, and we believe announcements will be made well in advance," added Ghosh.Analysts have raised the price target to Rs 4150, which is 20% higher than the current market price of Rs 3,457. The valuation gap between Infosys and TCS has shrunk based on forward earnings (FY15), Infosys is currently trading at price-to-earnings (P/E) multiple of 16.3 times, which is a near-13% discount to TCS' P/E of 18.4. At the beginning of the fiscal year in April, Infosys was valued at a 25% discount to TCS."We expect upside in software business due to pick-up in discretionary spending, as there is improvement in the US macroeconomic environment. Margin improvement is also likely due to cost-optimisation initiatives by the company. We expect consensus earnings upgrades," said Ashwin Mehta, analyst at Nomura, in a note.The gap in revenue growth between Infosys and TCS has reduced to 60 basis points in the September quarter of this fiscal, from 260 basis points in the fourth quarter of FY13. Analysts say re-rating of the Infosys stock is likely to continue as its valuations are at a steep 20% discount to TCS based on forward P/E multiples."We were big-time underweight on Infosys. (But) we are now more like neutral-ish," said a fund manager who did not want to be named. "It's not like people are big overweight, but given Murthy's solid reputation no one can dare be underweight either."Infosys, with 3.8% sequential growth in dollar-denominated sales in the September quarter, foxed analysts who had pencilled in growth between 2.5% and 3.5%. The company also raised annual sales growth forecast to 9-10% from 6-10% earlier. "We expect strong demand environment for IT services in 2014. Data points around Europe suggest either stabilisation or improvement. The discretionary spending currently being led by the US is likely to sustain," said Viju K George, analyst at JPMorgan.