Billionaire investor George Soros is causing a major stir in the world of philanthropy.

One of the richest men on the planet has transferred $18 billion of the wealth he built through his hedge fund over to his philanthropy.

His recent donations to the Open Society Foundations, which he founded, catapults it to the second biggest US philanthropic organization by sheer assets, eclipsed only by the Bill and Melinda Gates Foundation, according to the latest figures compiled by Foundation Center. 

Soros has also financially backed liberal issues in his adopted U.S. home, as well as Democrats, including Hilary Clinton's 2016 bid for the White House.

Soros' claim to fame rests on a famous trade back in 90s, where he bet against the British pound and won. He's been a legend ever since.

At 87-years-old, he's left day-to-day trading decisions to his chief investment officer, but said to keep a close eye on his portfolio. Last year he bet markets would fall if Trump won the White House - that's one bet - he lost.