The outlay marks the latest example of the industry’s enduring capacity to shrink fortunes, although the British billionaire may not be surprised, having once said: “If you want to be a millionaire, start with a billion dollars and launch a new airline.”

The airline business has long proved irresistible to a cohort of larger-than-life tycoons. From AirAsia Group’s Tony Fernandes to JetBlue Airways founder David Neeleman, some of the world’s most celebrated entrepreneurs have built fortunes shuttling people through the sky. But with air travel dwindling in lockdown, coronavirus has battered even those long hardened to the volatility and thin margins of the capital-intensive industry.

The market values of 10 large, publicly traded airlines linked to prominent magnates tracked by the Bloomberg Billionaires Index have fallen in value by $14 billion since the start of the year.

The crisis has already claimed plenty of victims. Earlier this year, Warren Buffett closed a losing bet on four major U.S. airlines, acknowledging that the investment had lost money for Berkshire Hathaway. It was his second go-round after earlier swearing off the sector.

Latam Airlines Group, Latin America’s largest carrier, whose shareholders include Chile’s Cueto family, sought bankruptcy court protection in New York. In March, Neeleman—who founded companies including JetBlue and Canada’s WestJet Airlines—unloaded more than 80% of his preferred shares in Brazilian carrier Azul SA after a margin call was triggered on a $30 million personal loan.

The crisis has also brought structural issues or simmering tensions to the surface. Norwegian Air Shuttle’s debt load forced it into a restructuring. The discount airline, whose co-founder Bjorn Kos was a former fighter pilot who challenged giants such as British Airways on trans-Atlantic routes, remains highly indebted and has warned it will likely need to raise more capital.

European budget carrier EasyJet, which is just emerging from a near total fleet grounding, has also contended with internal strife. Its founder and largest shareholder, Stelios Haji-Ioannou, launched a failed attempt to oust the executive leadership and block the purchase of Airbus planes he argued the carrier neither needed nor could afford.

Family conflict has actually helped shield South Korea’s Cho family, whose holding company Hanjin Kal owns shares in Korean Air Lines. and Jin Air. Hanjin Kal’s stock has soared 143% in 2020 because of a battle for control of the company. Shares in the individually traded airlines have declined.

It’s possible the industry may recover quickly enough to stanch some losses. There have been signs that travel demand has begun to perk up, fueling hopes that the stress on beleaguered carriers will ease.

But any return to business as usual is far off. Delta Air Lines slashed plans to restore some service after a resurgence in U.S. coronavirus cases undercut a nascent recovery in travel demand. Even with the restructuring, Virgin Atlantic said in a statement that it only expects to return to profitability from 2022.