An elite group of hedge fund managers must have awakened on Jan. 1 with an unusual type of hangover: their first annual loss. Large funds managed by King Street Capital Management, CQS, Pine River Capital Management, Metacapital Management, DW Partners and Libremax Capital were among those that lost money, or were on track to, in 2015 for the first time, according to people familiar with the firms and private performance information seen by Reuters.