Colin Huang’s ascent is one for the history books: In just six months, his fortune swelled by $25 billion — one of the biggest gains among the world’s richest people.

His Pinduoduo Inc., a Groupon-like shopping app he founded in 2015, has become China’s third-largest e-commerce platform, with a market value of more than $100 billion. In the first quarter, as the coronavirus pandemic caused most of the nation’s economy to grind to a halt, PDD’s active users surged 68 percent and revenue jumped 44 percent, the company said in May.

Now Huang, who has overseen the firm as its American depositary receipts have more than quadrupled in less than two years, has stepped down as chief executive officer.