History is uncertain whether it was John D Rockefeller or Henry Ford who became the world’s first billionaire in the early 20th century. It might be an arbitrary distinction, but ever since then generations of entrepreneurs have lusted after membership of the three-comma club.

With some 2,200 members this year, that club is not as exclusive as it used to be. It also has something of a revolving door. The tribulations of the stock market shunt people back and forth across the billionaire line with surprising frequency. The research firm Wealth-X identified 10 people who had remarkably dramatic swings in or out of billionaire status in the past year. Most made or lost their fortunes in China, which is now home to more billionaires than any other country.

FT Wealth details the world’s newly minted billionaires and profiles those who have just slipped out of the club.