A mutual fund is a collection of investment securities owned by the people who invest in it. When you invest in a fund you buy a share of the underlying securities.
Mutual funds are designed to make it easier to invest in securities. They also offer greater scope for risk diversification than investing in individual securities. A mutual fund is professionally managed by a fund manager.
The Swedish Pensions Agency offers a portfolio of around 800 funds, including the AP7 Equity Fund and the AP7 Fixed Income Fund.