Yu became the chief witness for the prosecution, and the trial process lasted five years. They reported their suspicions to banking regulators, and were rewarded with the indictments. Thomas Sung even once halted a bank run with the aplomb of James Stewart's George Bailey.Ībacus' managers did eventually learn of Yu's activities, and fired him and two others. Shanghai-born but all-American, Thomas Sung is a devotee of It's a Wonderful Life, an affection James could hardly help but exploit. That includes Jill Sung and Vera Sung, the English-speaking, Connecticut-raised sisters who had inherited day-to-day operations from their father, one of the bank's founders. Also, Yu spoke a dialect that even most of his fellow Abacus employees didn't understand. His activities were hard to track, because, as the film explains, Chinatown residents are more likely to make cash transactions than the average American consumer. The problem was a loan officer, Ken Yu, who asked borrowers for bribes and falsified income statements for mortgage applications. In fact, the bank had one of the lowest default rates in the country. The Chinatown-based bank also didn't package its mortgages into the sort of financial instruments that made The Big Short's machinations so arcane. As it happens, Abacus didn't deal in subprime.