Warren Buffett said Monday he plans to donate $3.6 billion of Berkshire Hathaway Inc. stock to five charities — one of his largest gifts ever.

The donations are occurring amid debate over how the richest Americans should use their money to help address income inequality and other economic imbalances.

Walmart Inc. heir Jim Walton largest gave away $1.2 billion of the retailer’s shares last week. And Home Depot Inc. co-founder Bernie Marcus said he’s planning to gift almost his entire $4.5-billion fortune before he dies.

Last week, a group including George Soros and Facebook Inc. co-founder Chris Hughes called for a wealth tax to help provide funds for fighting climate change and public health initiatives. Others such as Buffett have argued that they prefer to have entities such as the Bill & Melinda Gates Foundation oversee the charitable work.

Buffett’s gift brings the total amount of stock he’s donated to foundations to about $34 billion since making a pledge in 2006 to give away all his fortune, according to a statement Monday. The recipients include the Gates Foundation, as well as charities named for his late wife and ones run by his children.

Buffett has spent more than five decades crafting Berkshire Hathaway into a company with a market value of more than half a trillion dollars, spanning industries from insurance to manufacturing. Its success once made him the world’s richest man, though he has fallen back to fourth place as he steadily gives his fortune away.

The original 2006 supportedplan was later modified, and envisages posthumously donating all of the Berkshire stock within a decade after his estate is settled.

The billionaire investor has long the Gates’ charitable endeavors, and said in 2006 that he aimed for the stock donations to ramp up their foundation’s “already impressive effectiveness” addressing societal problems.

Buffett is also giving stock to the Susan Thompson Buffett Foundation, Sherwood Foundation, Howard G. Buffett Foundation and NoVo Foundation.