Donald Trump claims he is worth billions, but another wealthy businessman has his doubts.

The presumptive Republican presidential nominee's real estate success has not necessarily yielded the wealth Trump claims, entrepreneur Mark Cuban told WABC's "The Bernie and Sid Show" on Wednesday. He added that Trump is "not transparent enough for us to really know."

"I'm not so sure Donald knows what he's not good at. What he's done well is put his name on big buildings, right? He appears to have done well putting his name through a licensing arrangement on hotels and buildings. He's good at that. Now, whether or not that's made him a billionaire, I don't know," the Dallas Mavericks owner and "Shark Tank" investor said.

