A personal fortune in excess of $100 billion is all the more remarkable considering how much Omaha investor Warren Buffet has given away.

The Berkshire Hathaway chairperson's fortune has ballooned to $100.4 billion, Bloomberg reported Thursday in its Billionaires Index.

That milestone makes the 90-year old investor the sixth member of the $100 billion club - a group that includes Elon Musk, Jeff Bezos and Bill Gates.

Buffett's net value, as gauged by Forbes magazine, comes almost entirely from owning around a sixth of Berkshire, a company that is worth around $600 billion.

Berkshire's stock price has risen this month with its class A shares rising 15% and outpacing the 3.8% gain of the S&P 500 Index.

Even with the pandemic weighing heavily on many of Berkshire's businesses, the company posted a $36 billion profit in the fourth quarter - mainly as a result of paper gains on the value of its investments.

Buffet has donated large chunks of Berkshire stock yearly to the Bill and Melinda Gates Foundation and other charitable groups since 2006.

If he had not done so, he would be valued at more than $192 billion.

Buffett was once the wealthiest person.

Forbes ranks Buffet fifth on its list of the world's wealthiest people, next to Amazon's Jeff Bezos, Tesla's Elon Musk, LVMH's Bernard Arnault and his family and Microsoft co-founder Bill Gates, according to Reuters.

Jeff Bezos is the world's richest person with almost $180 billion in fortune, according to The Associated Press.