Jeff Bezos has sold nearly $3 billion worth of Amazon.com Inc. stock in the past week, just as the shares have suffered their worst losing streak in 13 years.

According to Securities and Exchange Commission filings Monday, Amazon’s founder and chief executive sold more than 517,000 shares Friday, worth about $1 billion. And earlier last week, he sold more than 968,000 shares worth about $1.84 billion.

Meanwhile, Amazon shares AMZN, +2.49% fell again Monday, their eighth straight day of losses and their longest losing streak since July 2006. The shares have fallen more than 12% during the slide, shaving more than $120 billion from Amazon’s market cap, which stands at about $873 billion.

The selloff hasn’t dented Bezos’s status as the world’s richest man — even though he’s lost nearly $15 billion in total net worth this year, his $110 billion fortune is still No. 1 in the world, according to Bloomberg’s Billionaires Index.

The proceeds from the stock sale could be going toward Bezos’s privately held space company, Blue Origin. Last year, he said he’s putting about a billion dollars a year from his own fortune into the company, and that he will likely spend more as the company gears up for its first commercial flights to space.