Amazon CEO Jeff Bezos laughs at a discussion at the Air Force Association's Air, Space and Cyber Conference in National Harbor, Md., Sept. 19, 2018.

Jeff Bezos has been cashing out Amazon stock: nearly $4.1 billion worth of shares in the past 11 days.

The Amazon CEO sold $579.8 million worth of shares on Friday, according to filings with the Securities and Exchange Commission. That's after he sold $1.65 billion worth of shares last Tuesday and Wednesday, as well as unloaded $1.8 billion worth of shares between Jan. 31 and Feb. 3, according to SEC filings.

The transactions were made as part of a prearranged 10b5-1 trading plan, according to the filings. Representatives from Amazon weren't immediately available to comment on the latest sale.