Now, Trump is opining on one subject with which he's very familiar: prenups. And more specifically, Mark Zuckerberg's prenup, should he marry his girlfriend.
After talking about JP Morgan's Jamie Diamond on CNBC's "Squawk Box" -- a topic Trump called "so boring" in comparison to what Zuckerberg would do in the event that he got married -- he started running through hypotheticals:
"So he's gonna be worth like $18, $19 billion, you're telling me he's got a girlfriend ... does he get a prenuptial agreement?" Trump said. "They get married, and then for some reason over the next couple of years they get divorced and then she sues him for $10 billion and she hits the jackpot ... In New York, she would get a big chunk of what he has."
Trump said he wanted to know who would handle the matter, that he'd like to look at the agreement, and that he himself would "one of the great professionals" to advise on the subject.
Co-anchor Andrew Ross Sorkin asked Trump what an "equitable" amount would be, to which Trump replied, "I'm notoriously cheap with these things, okay, because I think if she made $1 million, that would be very good."
This isn't the first time Trump has spoken out on the issue of prenups: When he gave a speech to 7,000 people in Melbourne last fall, his financial advice was to always get a prenup.
Trump's own ex-wife, Ivana, reportedly tried to challenge their prenuptial agreement -- which limited her to $25 million -- but failed in her effort.
Watch the CNBC video above.