Shark Tank’s ‘Mr. Wonderful’ Kevin O’Leary learned the hard way that movie sets don’t work like boardrooms on Marty Supreme

Shark Tank’s Kevin O’Leary isn’t used to taking orders, yet as an actor for the new movie Marty Supreme, the prolific investor had no other choice.

O’Leary has been a millionaire for more than 25 years and a prolific investor since then. He sold his software company SoftKey to Mattel for $4.2 billion in 1999. More recently, he has invested an estimated $8.5 million into about 40 companies in his role as a judge on Shark Tank since its inaugural 2009 season.

Yet, on the set of Marty Supreme...