Total U.S. retirement assets rose 6.3 percent to $18.9 trillion in the first quarter of 2012, up from $17.8 trillion on Dec. 31, 2011, according to data compiled by the Investment Company Institute.
The increase in retirement assets was driven in part by the rise in corporate equity values. The S&P 500 Total Return Index grew by 12.6 percent in the first quarter, for example. Retirement savings accounted for 36 percent of all household financial assets in the United States at the end of the first quarter.
There was $5.2 trillion in individual retirement accounts at the end of the first quarter, an increase of 7.3 percent from the end of the fourth quarter of 2011. Forty-six percent of IRA assets, or $2.4 trillion, were invested in mutual funds.
Defined contribution plan assets rose 7.1 percent from $4.5 trillion at the end of 2011 to $4.8 trillion in the first quarter of 2012. The bulk of those assets, $3.4 trillion, were held in 401(k) plans.
Government pension plans, including federal, state and local plans, held $4.7 trillion in assets at the end of March, a 5.5 percent increase from December. Private-sector defined benefit plans held $2.5 trillion in assets at the end of the first quarter, and annuity reserves outside of retirement accounts were another $1.7 trillion.
Mutual funds managed $2.8 trillion in 401(k), 403(b), and other DC plans at the end of March, up from $2.5 trillion at the end of December. Mutual funds managed 58 percent of DC plan assets at the end of the first quarter.
As of March 31, 2012, target-date mutual fund assets totaled $425 billion, an increase of 13 percent in the first quarter. Retirement accounts held the bulk of the target date mutual fund assets: 91 percent of target date mutual fund assets were held through defined contribution plans and IRAs.