George Soros, 85-year-old billionaire investor, is becoming more hands on in trading at his office for one simple reason—he’s worried about the economy.

Soros Fund Management recently swapped stocks for bearish investments, like gold and shares of various gold miners, as the firm begins to buckle down in anticipation of global weakness across various markets, Bloomberg reports. In particular, Soros is skeptical about China—he said the country’s debt-fueled economy looks a lot like the US just before the 2007-08 financial collapse.

Soros isn’t the only one worried and turning to gold. Billionaire investor Stan Druckenmiller says gold is his largest currency allocation and he’s staying away from much risk while central bankers tinker with the “absurd notion of negative interest rates.” [Bloomberg]