The fact that Trump Organization has been bailed out by the government and several banks should tell you that he's not the greatest businessman>really lucky guy
Again, making money on wall street is easy if you have large amounts of money to start with. Investing isn't about making money on one big score, it's generally about investing in multiple things. He's rich, but not as rich as he says. He works hard, but not nearly as hard as he wants you to think. He's not dumb, but he's definitely not smart.
Also, it's very unlikely for a business person to be worth more than the businesses he owns. Because unless he dug up treasure, it's not possible to own things you cannot afford. It's very unlikely for Donald Trump to be a multi billionaire if his company is hardly worth multi billions