Amazon Founder and CEO Jeff Bezos' net worth declined almost $9 billion in 2019 but he is still ending the year as the world's richest person. The 55-year-old's wealth dropped because of his divorce settlement with MacKenzie. The world's 500 wealthiest people tracked by the Bloomberg Billionaires Index added $1.2 trillion, boosting their collective net worth to $5.9 trillion.