Tesla's stock rose on Monday as Elon Musk bought more than 2.5 million shares, worth about $1 billion (€850 million), in his own company.
Shares of the electric vehicle maker jumped nearly 3.6% to $410.04 each.
Musk purchased various amounts of shares at different prices on Friday, according to a regulatory filing. The move may be viewed by the markets as the billionaire remaining confident in the company's future.
Earlier this month Tesla released a proposed pay package for Musk that would possibly make him the world's first trillionaire if he hits a series of extremely aggressive targets for the company over the next decade.
Tesla said in a regulatory filing that it will hand Musk shares worth as much as 12% of the company in a dozen separate packages if the company meets certain performance targets, including massive increases in car production, share price and operating profit.
If approved by shareholders, the new pay package could make Musk the world's first trillion-dollar executive, and would mark a new level of outsized pay in a country already known for extreme compensation. But the payoff is in shares, not cash, and the goals are extreme as well.
To get his first package of shares equivalent to 1% of the company, Musk would have to convince investors in the stock market that Tesla is worth $2 trillion (€1.70tn) in total, double what they value it today, and also hit several other milestones. To receive all the shares offered and make him the world's first trillion-dollar man would require that market value to then rise to $8.5tn (€7.21tn), double that of the world's most valuable company now, chipmaker Nvidia.
Tesla has seen a plunge in sales this year, largely due to blowback over Musk's affiliation with President Donald Trump. Tesla also faces intensifying competition from the big Detroit automakers and particularly from China.
Investors have grown increasingly worried about the trajectory of the company after Musk had spent so much time in Washington this year, becoming one of the most prominent officials in the Trump administration in its bid to slash the size of the US government.
Tesla is set to hold its annual shareholders meeting on 6 November, where investors will vote on the new pay package.
