U.S. commercial banks have increased their holdings of U.S. Treasuries over the past few years. Since December 2013, holdings of U.S. Treasuries have increased by $176.1 billion. On June 30, 2015, U.S. Banks held $660.4 billion of U.S. Treasuries, representing 4.31 percent of their total assets. This increase has occurred at the same time that concerns have arisen about increased volatility in the U.S. Treasury bond market. Regulators and government officials worry that the market’s volatility will pose a new risk to banks and decrease the attractiveness of U.S. Treasuries. Analysts worry that a rising rate environment will negatively impact banks with large bond portfolios.