Adam Neumann has been kicked out of the billionaire’s club.

Forbes has slashed the estimated net worth of WeWork’s long-haired cofounder to $600 million from $4.1 billion, following a botched IPO attempt that saw Neumann ousted as chief executive of the struggling office-sharing company.

Forbes calculated the steep discount by adding up his $500 million stake in WeWork with the $500 million he has profited from stock sales, and subtracting the nearly $400 million in debt he disclosed in the IPO filing of WeWork’s parent We Co.

We Co., in which Neumann holds an 18% stake, reportedly slashed its valuation to between $10 billion and $20 billion ahead of the fizzled IPO. But Forbes estimates that We Co. is worth “at most” $2.8 billion.

The rock-bottom assessment is “based on a multiple of the company’s revenues consistent with publicly traded competitor IWG,” and takes into account recent asset sales and “potential cash flow crunch,” Forbes said.

The 40-year-old Neumann, who first appeared on the list in 2016 with a net worth of $1.5 billion, had famously bragged of his ambition of becoming the world’s first trillionaire.

That now looks like an iffy prospect at best, as Neumann recently made headlines for alleged self-dealing, erratic behavior and drug use — including a report of a trans-Atlantic private jet trip last summer after which the crew found a “sizable chunk” of marijuana hidden in a cereal box on board.

Neumann, who remains We’s chairman, has a habit of spending lavishly. He and his wife, Rebekah, have spent close to $90 million on properties, according to the Wall Street Journal, including a sprawling Hamptons estate, a 60-acre compound in Westchester and a four-condo mega-residence off Gramercy Park.