By the time Citigroup's ( C) board of directors replaced CEO Vikram Pandit in October, 2012, shares had already risen from $25 earlier that summer to a price of $35. Still, even after that rebound, shares traded well below book value of around $50, a sure sign that many investors were still troubled by Citigroup's performance. A big part of the problem resided in the company's bloated overhead, so the board promoted Michael Corbat to CEO. Corbat had a longstanding track record at the bank and was known for a tight focus on costs and profit margins. >>5 Must-See Charts to Trade in April Fast forward to March 2013, when Corbat delivered his first major presentation to Wall Street analysts, and many came away impressed. Indeed, shares have already begun to strengthen further under Corbat's watch. The new CEO discussed room for improvement in Citigroup's various banking and lending divisions, establishing clear yet achievable targets to be met by 2015. The key takeaway: Though revenue growth will likely be modest, efficiency improvements will mean that EPS is positioned to rise from under $3 a share in 2012 to around $5.50 by 2015. If Corbat can meet those targets, then shares are likely to move back up to book value, or even higher, in coming years.