Dallas Mavericks owner and Three Commas Club member Mark Cuban doubts that Donald Trump is a fellow billionaire.

He elaborated on this line of thought on a New York radio program last week. And in several Twitter posts Wednesday morning, Cuban explained why Trump will be more beholden to the donor class than Hillary Clinton after calling him a "puppet president."

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The outspoken NBA owner went on New York radio program “Bernie and Sid” on June 1 and revealed his alleged inside knowledge. Cuban said he’s seen Trump’s FEC filings and that Trump is “horrible” at handling his business. From the radio interview (via Buzzfeed):

“He’s good at [branding]. Whether or not that’s made him a billionaire, I don’t know,” Cuban said. “He’s not transparent enough for us to actually know.”

He believes the reason that Trump is constantly endorsing products from steaks to wine to playing cards is because he’s desperate for money.

On Forbes' billionaire list, Trump (Net worth: $4.5 billion) remains several dozen spots higher than Cuban (Net worth: $3.2 billion). But Cuban insisted on the radio show that there’s no way Trump has more money than him. The “Bernie and Sid Show” via Buzzfeed’s transcription again:

“It’s not even close, I [have more money],” Cuban said. “Before all the Trumpians jump on me on who has more money, the reason I know is when you file your federal election campaign reports, you have to list all your cash and liquid securities and bonds. You have to list them one by one. So we know without any question that as of May 27, Donald doesn’t have more than $165 million in cash and securities and bonds.

“And trust me, I’ve got a lot of more than that in cash, securities, and bonds,” he continued. “And so you know, I’m willing to bet dimes against dollars that that’s pretty much what he’s got.”

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A week later Cuban took to Twitter to continue his Trump-is-not-a-billionaire campaign. He said Trump needs to calm down because “he doesn’t have the cash to fund his campaign, he needs to appease donors quickly.” Cuban said Trump will need to grovel to donors and “hidden” video eventually will reveal he’s telling private fundraisers what they want to hear.

He finished his Twitter expose with this coup de grâce.

Cuban seemed to entertain the idea of a Trump presidency last year. He’s no longer on board, though he did say he could be Trump’s (or Clinton’s) vice president.

See who Donald Trump's actual vice presidential candidates can be in the gallery above.