The Swiss National Bank's US stock investment portfolio has shrunk for the second consecutive quarter.

According to the 13F report submitted to the U.S. Securities and Exchange Commission on Monday, the Swiss National Bank's foreign exchange reserves held in the form of U.S. stocks shrank in the first quarter of this year. As of March 31, the central bank held shares in 2,397 U.S. listed companies worth a total of $141.6 billion, a 5.8% decrease from three months ago. Approximately a quarter of the Swiss bank's foreign exchange reserves are invested in the stock market, with some of it invested in U.S. stocks.