When Kevin O'Leary chooses companies to invest in on Shark Tank, he simply follows the data. It's a strategy that has led him to prefer women-led companies.

"It's not because I'm sexist," O'Leary said at the Inc. Women's Summit in New York City on Monday. "But because I'm getting better returns."

O'Leary has invested in more than 40 companies across Shark Tank's nine seasons. His company, O'Shares Investment, found that about 95 percent of the women-led companies met their financial targets, compared with just 65 percent for businesses with male leaders.

"That's because men were setting targets that were not achievable. Maybe that's the aggressive nature of how they work," O'Leary said. "Women don't waste time."

O'Leary was joined on stage by Donna Khalife, co-captain and COO of Surprise Rides; Sara Margulis, co-founder and CEO of Honeyfund.com; and Tracey Noonan, co-founder and CEO of Wicked Good Cupcakes. Each entrepreneur scored a deal with O'Leary on Shark Tank, and the three companies are among his most successful investments from the show.

The group discussed some of the keys to good business, like being able to fire friends or family members who work for you. All three women entrepreneurs work with relatives, including their husbands, and talked about the importance of realizing when something isn't working. They also discussed the importance of setting reasonable but lofty goals.

"Setting achievable goals and dreaming big are not mutually exclusive. They can work together," Khalife said at the event. "You have to dream big to even have a chance to land somewhere that you're proud of."