Billionaire investor George Soros raised his stake in the SPDR Gold Trust in the first quarter, according to a government filing.

As of March 31, Soros Fund Management LLC held 319,550 shares in the exchange-traded product backed by the precious metal, compared with 85,450 shares at the end of the fourth quarter, a U.S. Securities and Exchange Commission showed Tuesday.

The SPDR trust is the biggest exchange-traded product backed by gold.