Amazon chief executive Jeff Bezos had 150 billion reasons to smile this morning.

Thanks to a boost from Amazon Prime Day in the United States, Bezos officially became the wealthiest man in modern history, with his net worth reaching more than US$150 billion.

In Aussie dollars, that makes for a cool $202.5 billion.

For perspective, this figure makes Bezos worth more than Microsoft co-founder Bill Gates and Google co-founder Larry Page combined.

Berkshire Hathaway's Warren Buffett is the third richest person on the planet behind only Bezos and Gates. But the Oracle of Omaha trails Bezos by nearly US$70 billion.

Bezos, who also personally owns The Washington Post and space exploration company Blue Origin, has most of his net worth tied up in Amazon stock. He is the company's largest shareholder, with a more than 16 percent stake.

Amazon's growing clout in retail, cloud computing, media and numerous other areas has put the company closer to surpassing Apple as the world's most valuable company.

Amazon's stock is up nearly 60 percent this year and the company has a market value of more than US$890 billion. Apple's market value is a little more than US$935 billion.

Amazon will report its second quarter results on July 26. Analysts are forecasting a more-than-40-percent jump in sales and a more than sixfold surge in earnings per share.

The company has reliably topped Wall Street's forecasts and if Amazon delivers another blowout quarter, the company could soon find itself worth more than US$1 trillion.

That would put the net worth of Bezos closer to US$175 billion.