pension4A pension fund is any plan, fund, or scheme which provides retirement income.

Pension funds are important to shareholders of listed and private companies. They are especially important to the stock market where large institutional investors dominate. The largest 300 pension funds collectively hold about $6 trillion in assets.[1] In January 2008, The Economist reported that Morgan Stanley estimates that pension funds worldwide hold over US$20 trillion in assets, the largest for any category of investor ahead of mutual funds, insurance companies, currency reserves, sovereign wealth funds, hedge funds, or private equity.Although the (Japan) Government Pension Investment Fund (GPIF) lost 0.25 percent, in the year ended March 31, 2011 GPIF was still the world's largest public pension fund which oversees 114 trillion Yen ($1.5 trillion)