Former Uber Technologies CEO and co-founder Travis Kalanick walks on the floor of the New York Stock Exchange during the company's IPO May 10, 2019.

Uber's former CEO Travis Kalanick went on a selling spree late last year, dumping almost all of his shares in the ride-hailing company between November and December. In doing so, he left more than $1 billion on the table.

Uber shares rose as much as 10% in extended trading on Thursday, surpassing $40, after the company reported better-than-expected fourth-quarter results and said it would reach EBITDA profitability ahead of schedule.

The story has brightened modestly for Uber, which struggled last year after its market debut in May, as investors questioned whether the cash-burning business would be able to scratch its way to profitability. After its IPO debuted at $45, the stock sank as low as $25.99 in mid-November. At its after-hours peak on Thursday, it was up 56% from its lowest close.

Had Kalanick held onto his shares, they'd be worth $1.2 billion more today than they were when he divested. Kalanick left the Uber board on Dec. 24, to "focus on his new business and philanthropic endeavors," the company said, just as he was unloading the last of his shares. His latest venture, CloudKitchens, rents out space to restaurateurs for delivery-based businesses.

Kalanick was ousted as Uber's CEO in 2017 after a litany of concerns emerged surrounding the company's culture and workplace environment and its treatment of drivers and riders. Dara Khosrowshahi, the former Expedia CEO who succeeded Kalanick, said in December that he was "enormously grateful for Travis' vision and tenacity while building Uber."

Kalanick started selling shares in November after the post-IPO lockup period expired, dumping 20% of his stake on Nov. 6, at $26.99 a share, according to filings. Over the next weeks, he sold the rest at prices ranging from $26.63 to $30.47.

In total, Kalanick netted about $2.8 billion from his stock sales.

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