Citigroup ( C) is another staid financial sector name that's getting bought up by institutional investors in 2013. Citi is one of the biggest banks in the world, with 1.9 trillion in assets and more than a quarter of a million employees. Despite struggling to survive the financial crisis of 2008, this $152 billion bank has re-emerged as strong as ever -- as long as investors are cognizant of changes to Citi's core business, that is. >>5 Stocks Poised to Pop on Bullish Earnings Citi isn't the same company that it used to be. Since coming out of the Great Recession, the risks that the firm is allowed to take have been restricted by rule. That doesn't just limit the implications of an economic hiccup for investors -- it limits Citi's potential upside too. Remember, less risk in the bad times means less reward in the good times too. That said, since Citi has returned to actually being a bank again, its good times haven't exactly been lacking. Net margins still weigh in deep in the double digits; now the key is that it also sports a loan book that's a whole lot less scary. A new CEO in Michael Corbat isn't likely to bring about many insane changes in 2013. Instead, expect the firm to keep executing well. As interest rates start floating higher in the intermediate term, so too should Citi's profits. That makes buying in a low-rate environment all the more attractive. Institutions picked up 82.3 million shares of Citigroup last quarter.