Ackman, Dinan, Paulson Lead The Way In First Half

After having mediocre to bad investment returns, Bill Ackman's Pershing Square is sitting on one of its largest gains of the past few years. The long/short equity hedge fund is up 25% in the first six months of the year, making it the top performer of the first half among hedge funds.

Ackman outshines other activists

Ackman has scored a good year in his largest longs, Air Products & Chemicals, Inc. (NYSE:APD) and Canadian Pacific Railway (NYSE:CP) (TSE:CP) and in some of his new positions including, Allergan Inc (NYSE:AGN) and Platform Specialty Products Corp (NYSE:PAH).

Other noted hedge fund managers have also done...