Judging by the fact that Ironwood Pharmaceuticals, Inc. (NASDAQ:IRWD) has witnessed falling interest from hedge fund managers, logic holds that there lies a certain "tier" of fund managers who sold off their positions entirely heading into 2013. Interestingly, Wayne Holman's Ridgeback Capital Management sold off the biggest stake of the 450+ funds we track, worth an estimated $27 million in stock., and Joseph Edelman of Perceptive Advisors was right behind this move, as the fund sold off about $1 million worth. These bearish behaviors are important to note, as aggregate hedge fund interest stayed the same (this is a bearish signal in our experience).