The founder of high-flying Chinese e-commerce group Pinduoduo has stepped down unexpectedly as chairman.
Colin Huang is China's seventh richest person and is worth more than $50bn from his stake in the online firm.
Mr Huang's exit comes as Pinduoduo overtook rival tech giants JD.com and Alibaba with 788m annual active buyers on its platform last year.
But his company has been criticised for its work culture following the death of two employees recently.
Mr Huang will explore "new, long-term opportunities", the company said in a statement on Wednesday, as it released figures stating it was now China's largest e-commerce firm.
Shares in Pinduoduo, valued at close to $200bn (£143bn), fell by nearly 8% following the news, wiping about $4bn from Mr Huang's wealth.
The former Google employee was briefly ranked the second-richest person in China last year, following a surge in sales at his e-commerce business.
Pinduoduo's 788m active buyers in 2020 overtook Jack Ma's Alibaba's 779m annual shopper count for the first time.
Its novel features include team buying, where customers come together to purchase more units at a lower price. They can also play games on the site and are sometimes rewarded with gifts.
'Journey of exploration'
In a letter to shareholders, Mr Huang said: "As the founder of this company, I am probably the most suitable person to take on this task by stepping out of the business and the comfort zone to embark on a journey of exploration."
Pinduoduo has appointed Chen Lei as the company's new chairman. Mr Chen was a classmate of Mr Huang's at the University of Wisconsin-Madison and was appointed chief executive in July 2020.
The e-commerce firm's rapid growth has been powered by cheap deals but it continues to post losses.
Pinduoduo has repeatedly sought more funding, raising roughly $9bn from investors since its Wall Street stock market launch in 2018.
The online grocery market has become highly competitive in China as more shoppers buy daily meal ingredients from their phones following the pandemic.
But there has been widespread online criticism of the intense work culture across China's booming tech industry.
In December, the death of a Pinduoduo employee who collapsed after leaving work sparked heavy criticism of its work culture.
Many tech workers follow a "996" schedule, based on working daily from 9am to 9 pm, six days a week.