Nvidia CEO Jensen Huang sold 100,000 shares of the chipmaker’s stock on Friday and Monday, according to a filing with the U.S. Securities and Exchange Commission.

The sales are worth nearly $15 million at Tuesday’s opening price.

The transactions are the first sale in Huang’s plan to sell as many as 600,000 shares of Nvidia through the end of 2025. It’s a plan that was announced in March, and it’d be worth $873 million at Tuesday’s opening price.

The Nvidia founder still owns more than 800 million Nvidia shares, according to Monday’s SEC filing. Huang has a net worth of about $126 billion, ranking him 12th on the Bloomberg Billionaires Index.

The 62-year-old chief executive sold about $700 million in Nvidia shares last year under a prearranged plan, too.

Nvidia stock is up more than 800% since December 2022 after OpenAI’s ChatGPT was first released to the public. That launch drew attention to Nvidia’s graphics processing units, or GPUs, which were needed to develop and power the artificial intelligence service.

The company’s chips remain in high demand with the majority of the AI chip market, and Nvidia has introduced two subsequent generations of its AI GPU technology.

Nvidia continues to grow. Its stock is up 9% this year, even as the company faces export control issues that could limit foreign markets for its AI chips.

In May, the company reported first-quarter earnings that showed the chipmaker’s revenue growing 69% on an annual basis to $44 billion during the quarter.