Uber Technologies co-founder and ex-CEO Travis Kalanick is unloading his shares in the ride-hailing company at a blazing fast pace, selling another $166 million worth of stock between December 11 and December 13, or more than $350 million of his stock just this month.

Overall, this brings the 43-year old’s proceeds from Uber’s stock sale to over $2.1 billion since a share lockup that ended on November 6, Bloomberg reports. Kalanick’s remaining stake in Uber now accounts for about a fifth of his estimated $3 billion fortune, down from around 75 percent before the lockup.

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Uber co-founder Garrett Camp is also reducing his stake in the company, but not on the same speed as Kalanick; he sold around $35 million worth of shares, which is a fraction of his $2.1 billion fortune. Uber’s CEO Dara Khosrowshahi on the other hand bought $7 million worth of shares on November 18.

Uber’s shares rose by 5.5 percent in New York, following a report saying that the company is looking to sell its Uber Eats business in India. However, the stock has been down by 33 percent since the company’s May public offering as Uber is faced with many regulatory challenges and investors question its ability to return a profit.

The company is dealing with a number of issues, including a fatal incident involving one of their self-driving prototypes in Arizona. Uber also faces problems in California, where a new law is now giving gig-economy workers the right to a minimum wage, as well as in the UK, where regulators revoked their license in London, its biggest European market. The company has appealed the decision.