Citigroup's ( C) shareholders are a patient lot, but how long must they wait for the financial services behemoth to find its groove? Over the past 15 months, investors have watched the stock trade sideways while its peers have outperformed. Through acquisitions, management changes, assets sales, new hires and a blockbuster year for most of its competitors, the stock hasn't done much. Since the start of 2005, Citi shares have added roughly a dollar, closing Tuesday at $47.60. Still, bulls keep the faith. Last week, Richard Bove, analyst at Punk Ziegel & Co., called Citigroup his favorite stock. "We look forward to many years of Mr. Prince's leadership," Bove said in a recent report, referring to CEO Charles Prince, who is in the process of succeeding Sandy Weill as chairman. Many institutional shareholders that have Citigroup as a large percentage of their portfolio show no interest in selling. Amid the cheerleading, however, Citigroup remains a laggard, and even some fans are starting to wonder if anything can kick the funk. Shares have risen just 6.7% this year. Two peers, JPMorgan Chase ( JPM) and Deutsche Bank ( DB), have seen their shares rise 19.3% and 29.2%, respectively. Other large global banks have seen even more of a lift, with Goldman Sachs ( GS) running up 40.5% and Morgan Stanley ( MS), despite all its woes, gaining 11.8%. The picture gets bleaker going further back in time. In mid-2001, shares of Citigroup were almost exactly where they are now, hovering around $48. And while investors seem willing to hang on for some long-awaited upside, others are getting antsy. "You can see the great stock price performance of the big brokers, and it is not like Citigroup is doing terribly," said Michael Hussey, senior adviser at Bufka & Rogers, a large holder in the stock. "I do think that the stock is undervalued, but I don't see some obvious tactics to get it up."