Agnostic to his Herbalife bet, Ackman "has widely underperformed the S&P 500 since its EOY 2012 inception: 7.1% since inception net of fees vs. 84% for the S&P 500. Their original flagship fund's (2004 inception) track record is outstanding with returns of ~20% per annum."
So his first fund killed it, he made a name for himself, raised a ton of money, and has literally cost his investors 75% of their returns to date in the market.
He's personally worth $1,400,000,000 now as a result.
Every fund pitch everywhere comes with the disclaimer "Past performance is not an indicator of future success" because of funds like Ackman's.