U.S. retirement plans held $13.4 trillion in assets March 31, down about 22% from $17.1 trillion at the end of the first quarter of 2008, according to the Investment Company Institute.
Retirement savings accounted for 33% of all U.S. household financial assets at the end of the first quarter.
The ICI, Washington, has based those estimates on data from its own database, the Federal Reserve and other sources.