The CEO of the company stands in the factory during a press event.
According to financial disclosures published late Tuesday, Musk has sold another 934,090 shares in his electric car and solar business.
The 2012 compensation package granted to Musk allowed him to buy 1.6 million shares of the company at a strike price of $6.24 per share.
The Wall Street Journal reported that Musk increased his holdings in the company from 170.5 million shares to over 177 million shares.
Musk has been on a selling spree in order to pay his taxes.
In the first week of November, the celeb-CEO asked his tens of millions of followers if he should sell 10% of his stake in the company. They voted yes. A large part of the sales that followed the poll were part of a plan that Musk adopted in September.
CEOs can trade their own equity as part of a pre-announced portfolio management plan. They have to make sure that they know when and how they will trade to protect themselves from accusations of insider trading.
Musk is the world's wealthiest person after the shares of his company rose more than 50% this year. According to estimates by Forbes, his net worth is over $275 billion.
Musk has ownership stakes in both companies. He doesn't take a salary or cash bonuses, and has not sold a lot of shares in the company until this year. He took out large loans against a portion of his shares.
Musk never paid a large amount of taxes relative to his net worth because taxpayers only pay taxes on income or stock once it is sold, according to ProPublica.
Elizabeth Warren, D-Mass., said that Musk was freeloading off everyone else because he didn't pay federal income taxes.
Musk is expected to pay the largest individual tax bill in US history, with federal and California income taxes estimated to top $11 billion. He will have to pay this tax bill in order to receive compensation of more than $23 billion in the form of stock options that would otherwise expire in August.
The centi-billionaire spoke about his wealth and tax strategy during a number of December press appearances, including interviews with the Financial Times and Time Magazine, which both named him person of the year for 2021.
On Tuesday last week, Musk sat with the conservative satire site The Babylon Bee, capping off his year-end publicity efforts. He said during the interview that he sold enough stock to get to 10% plus the option exercise stuff.
On the next day, Musk said, "This assumes completion of the 10b sale." When the 10b preprogrammed sales are complete. There are a few more to go, but almost done.
By some estimates, Musk still has more than a million more shares to sell to reach his 10% November target. The sum total he plans to sell to hit that goal was not responded to.
CNBC's Thomas Franck and Robert Frank contributed.
