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, where he played ruthless millionaire businessman Milton Rockwell opposite Timothée Chalamet’s character Marty Mauser, O’Leary learned that just because he calls the shots in every other aspect of his life, doesn’t mean he was holding the reins on set.

(Minor to major spoilers follow for Marty Supreme.)

“I learned my lesson that film sets are not democracies. I’m not used to being told what to do. I do the telling,” O’Leary told Variety. “We shot something 20 times and I said to Josh [Safdie], ‘OK, I think we got it. We can move on.’ He said, ‘What the f*** are you talking about? There’s no moving on until I say we’re moving on.’”

O’Leary’s contributions to the film

Yet, although O’Leary was not in control on set, Safdie and co-writer Ronald Bronstein were happy to include his notes for a character that echoed some of his own personality. One of the most prominent was a monologue delivered by Rockwell to Mauser in which he claimed to be a “vampire” born in 1601.

O’Leary also contributed to Rockwell’s look, and leveraged his knowledge as a horophile when choosing the two watches his character wore on each wrist, one set for New York and the other for Tokyo time. 

O’Leary refused to wear a prop watch or to wear a watch he didn’t own. Instead, he went on a global hunt for era-appropriate pieces to wear in the film.

He called up Rolex and secured a Patek Phillipe from the 1950’s which he admittedly purchased “at a crazy price.” The other, a Seiko-made watch called “Super” from 1952 was impossible to find on the secondary market. In the end, “Seiko found one — it might have come from some museum — and they gifted it to me,” O’Leary told the New York Times.

Maybe one of O’Leary’s most memorable scenes was when he literally smacked the Oscar-nominated Chalamet on his bare butt with a real ping pong paddle in order to bring more authenticity to a pivotal scene that he said required 40 takes and took until 4 a.m. to finish.

To be sure, one of his biggest qualms with the film was the ending, which wraps up poorly for his character, and which he called “absurd,” according to Variety.

“I had lots of fights with Ronnie [Bronstein]— well, not fights, but I said, ‘Guys, this Marty Supreme guy, I would never let anybody [expletive] me over like this. This would never happen to me, ever. And he is not paying an adequate price,’” O’Leary told the New York Times.

Yet, not all of the Shark Tank judge’s suggestions were incorporated into the final cut. Apparently, the investor and rookie actor suggested changes for the film’s ending, including that Chalamet’s character’s love interest, Rachel Mizler (played by Odessa A’zion) should die in childbirth in order to add more suffering to an otherwise “kumbaya” ending. In the end, Safdie considered the change but didn’t incorporate it as he thought it was too “sick,” according to Variety.

A reluctant “employee”

O’Leary is not used to being an employee. Just before he sold SoftKey, the company had acquired many of its competitors and stood as the second-largest consumer software company at the time with 2,000 employees. 

As a judge on Shark Tank, he is also used to entrepreneurs seeking him out for his advice, even though he is often brutally honest to contestants on the show. This includes the founders behind The Lip Bar, whom O’Leary told “the chances that this is a business are practically zero.” The lipstick company raised $6.7 million in a 2022 funding round and later went on to tease O’Leary via billboard advertisement.

O’Leary was scouted by director Josh Safdie for the part of Rockwell in Marty Supreme partly because of his reputation on Shark Tank. In fact, according to O’Leary, Safdie sought him out for the role of Rockwell for the same reason television producer Mark Burnett liked him for Shark Tank, “We’re looking for a real asshole,” Safdie reportedly told O’Leary.

Safdie, who previously co-directed A24’s Uncut Gems, accepted a flight on a private jet to O’Leary’s lake house in Muskoka, Canada, to hear him read for the part. As O’Leary admittedly explores other acting opportunities (although he is reportedly waiting for the promotional cycle to end before taking another role) he said he is happy to play the antagonist—and would ideally love to play a bond villain.

“I say this asshole thing’s starting to work for me,” O’Leary told Vanity Fair.