(Bloomberg) -- It’s not all bad news in the co-working world.

As investor doubts mount in the run-up to a potential initial public offering for WeWork parent We Co., shares of Swiss rival IWG Plc have been on a tear this year, adding more than $500 million to the net worth of founder and Chief Executive Officer Mark Dixon. Toward the end of 2018, the U.K. native was at risk of losing his status as one of Britain’s few billionaire CEOs, but IWG has almost doubled since then -- the third-best performance in the FTSE 250 Index.

Dixon, 59, is now worth about $1.7 billion, according to the Bloomberg Billionaires Index. He declined to comment through a spokesman.

WeWork founder Adam Neumann, meanwhile, has seen his fortune drop by more than $10 billion, at least on paper, as estimated Wall Street valuations for the company have tumbled as low as $15 billion amid scrutiny of Neumann’s unorthodox financial dealings with the firm. Earlier this year, some bankers said its valuation as a public company could soon reach $65 billion.

Dixon, who previously worked as a baker, burger-flipper and encyclopedia seller, knows a thing or two about changing fortunes. He first became a billionaire in 2000 after the IPO of Regus Plc, the IWG predecessor he founded about a decade earlier. Much of his wealth evaporated when the dotcom bubble burst and Regus’s U.S. arm filed for bankruptcy. Even last year, shares of IWG slumped 21% in a single day as profits declined and the company ended potential takeover talks with private equity firms.

IWG, the world’s biggest operator of serviced offices, comprises most of Dixon’s wealth. He now lives in Monaco, where residents pay no capital gains taxes, and his other investments include vineyards and a 7.8% stake in British property developer Inland Homes Plc. Dixon has sold about $300 million of IWG shares during the past three years, but is still its biggest investor with a 27% stake, according to data compiled by Bloomberg.

WeWork’s growth has prompted IWG to defend its turf. Last month, the company said it’s accelerating a franchising push to maintain its scale advantage over its U.S. rival. IWG also has sought to bolster Spaces, the flexible-office brand it bought five years ago that emphasizes design.

Dixon, in an interview last month, said he hopes WeWork’s IPO will provide a lift for his own company.

“The playing field will become level,” he said.

--With assistance from Jack Sidders, Tom Metcalf and Sophie Alexander.

To contact the reporters on this story: Ben Stupples in London at bstupples@bloomberg.net;Neil Callanan in London at ncallanan@bloomberg.net

To contact the editors responsible for this story: Pierre Paulden at ppaulden@bloomberg.net, Peter Eichenbaum, Steven Crabill

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