It is possible that positions have since changed. The firms mentioned either declined to comment or did not respond to a request for comment.
Less than a year ago, Daniel Loeb's Third Point invested with Allergan and praised the company's management team, including Chief Executive Brent Saunders. In a July 2015 letter to clients, Loeb was particularly happy to hear Saunders talk about the opportunity for a transformational transaction.
That was after Allergan had already merged with Actavis but before the Pfizer deal was announced late last year.
The risk of the deal being scuttled also hurt players who had made smaller bets on Allergan.
Scott Ferguson who runs Sachem Head Capital Management, is invested with Allergan and lost an estimated $78 million on paper, according to Symmetric.io. Ferguson was not available to comment. Similarly, Keith Meister's Corvex Management lost an estimated $33.6 million, while Philippe Laffont's Coatue Management lost an estimated $38.4 million, the Symmetric.io data show. The firms were not immediately available to comment.