"Foreign capital inflows are playing an important role in the U.S. economy by bridging the gap between domestic supplies of and demand for capital. In 2008, as the financial crisis and global economic downturn unfolded, foreign investors looked to U.S. Treasury securities as a 'safe haven' investment, while they sharply reduced their net purchases of corporate stocks and bonds. In the first two quarters of 2009, foreign capital inflows dropped sharply, reflecting an increase in savings by households and businesses and a continued decrease in U.S. liabilities to foreigners reported by U.S. banks and securities firms. Foreign investors now hold more than 50% of the publicly held and traded U.S. Treasury securities. The large foreign accumulation of U.S. securities has spurred some observers to argue that this large foreign presence in U.S. financial markets increases the risk of a financial crisis, whether as a result of the uncoordinated actions of market participants or by a coordinated withdrawal from U.S. financial markets by foreign investors for economic or political reasons. […] This report relies on a comprehensive set of data on capital flows, represented by purchases and sales of U.S. government securities and U.S. and foreign corporate stocks, bonds, into and out of the United States, that is reported by the Treasury Department on a monthly basis."
CRS Report for Congress, RL32462