Updated from 3:04 p.m. EDTIt took Oppenheimer only one month after bearish bank analyst Meredith Whitney's departure before it changed its mind on Citigroup's ( C) prospects. Oppenheimer analyst Chris Kotowski on Tuesday initiated coverage of Citigroup with a perform rating in a research note that says the embattled financial institution is "perhaps not hopeless." He argues that Citi has "a number of powerful franchises that could drive substantial value in future years." The move is an about-face for Oppenheimer, where Whitney gained acclaim in late 2007 for foreseeing many of Citi's problems, before the decline of the housing market escalated into a massive global economic crisis. Whitney, who worked at Oppenheimer for more than a decade, left the firm last month to start her own stock advisory group. Whitney had some particularly harsh calls for Citigroup, most of which eventually came true. In 2007, she predicted that Citigroup would need to oust then-CEO Charles Prince, slash its dividend further and sell off assets to raise more capital. After Whitney announced she would leave on Oppenheimer, the firm dropped its coverage of Citigroup until Kotowski came out with his research report that stated he believed Citigroup could work through its problems. "Investors need to move beyond the grief of seeing Citi as a penny stock and focus on the fact that this is a strategically important institution with many strong businesses," Kotowski wrote in his note. He goes as far as saying that Citi's credit card operations, though currently stressed by losses like most others, "are indeed a powerful and valuable franchise."