Bezos notified the Securities and Exchange Commission earlier this month that he intends to sell 300,000 shares, adding to the $6.1m (£4.3m) he made in February and the $20m (£14.1m) he made in May last year.
Amazon shares closed at $14.68 (£10.37) on Friday, a dramatic fall from May's price of $59.94 (£42.35), when Bezos sold 368,650 shares.