Nvidia Corp. Chief Executive Officer Jensen Huang has started selling the chipmaker’s stock, his first transactions under a plan that allows him to offload up to $865 million worth by year’s end.

Huang disposed of 100,000 shares over a two-day period of June 20 and June 23 for $14.4 million, according to a filing Monday with the Securities and Exchange Commission. Huang’s sales are part of a new 10b5-1 plan adopted in March and disclosed last month in Nvidia’s quarterly report.

Huang is the world’s 12th richest person with a $126 billion fortune, which is almost entirely made up of Nvidia shares, according to the Bloomberg Billionaires Index. The CEO has sold more than $1.9 billion in Nvidia stock, according to index calculations.

Nvidia didn’t immediately respond to a request for comment outside of normal business hours on the sales.

Huang’s pre-arranged trading plan, common among billionaires and executives who want to cash in some stock without spooking investors, gives him the option to sell 6 million shares by the end of the year. That amount would be valued at $865 million at Monday’s closing price of $144.17. Another filing on Monday shows Huang plans to sell another 50,000 shares imminently.

Billionaire Nvidia board director Mark Stevens has also been selling stock. He disposed of more than 600,000 shares for about $88 million on June 18, according to a separate filing on Monday.

Earlier in June, the investor filed a proposal to dispose of up to 4 million shares of the chipmaker’s stock and has so far offloaded more than 2 million. Unlike Huang and other board directors, Stevens doesn’t sell under a 10b5-1 plan.

Stevens has a net worth of $9.8 billion, according to Bloomberg’s wealth index.