Bill Ackman: Hedge fund billionaire becomes tennis pro and is ridiculed

Others, however, have nothing but ridicule and criticism for the move. Andy Roddick, for example, the former world number one, suspects that Ackman bought his wildcard. "Bill Ackman, who is a huge tennis fan and promoter, funds the PTPA (Professional Tennis Players Association, ed.), takes care of everything, wanted to participate in a professional tournament. So there was obviously an exchange of something," he said on the podcast "Served," according to CNN. "It was the biggest joke I've ever seen in professional tennis," Roddick summed up.

So, did Ackman pay money to play? In response to a CNN inquiry, the ATP pointed to its wildcard policy, stating that tournaments "may not receive compensation, nor may players offer compensation in exchange for receiving a wildcard."