Sovereign wealth funds have been around for generations, and President Donald Trump wants the federal government to join in on the trend. But there are a few problems — namely, it’s never been done in a democracy as complex as the United States. 

Perhaps the most well-known sovereign wealth fund, an investment fund created by a government, is Saudi Arabia’s Public Investment Fund, which manages about $925 billion in assets. The funds can invest in anything, including real estate, infrastructure, hedge funds, and corporations, with the purpose of benefiting the country’s economy.