Investing in funds provides a simple and effective method of diversification. Because your money is pooled together with that of other investors, each fund is large enough to diversify across hundreds and even thousands of individual companies and assets. A pooled (or collective) investment is a fund into which many people put their money, which is then invested in one or more asset classes by a fund manager.
There are different types of pooled investment but the main ones are:
Most pooled investment funds are actively managed. The fund manager researches the market and buys and sells assets to try and provide a good return for investors.
Trackers, on the other hand, are passively managed; they simply aim to track the market in which they are invested. For example, a FTSE100
tracker would aim to replicate the movement of the FTSE100 (the index of the largest 100 UK companies).
Trackers might do this by buying the equivalent proportion of all the shares in the index. For technical reasons, the return is rarely identical to the index, in particular because charges need to be deducted.
Trackers tend to have lower charges than actively managed funds. This is because a fund manager running an actively managed fund is paid to invest so as to do better than the index (to beat the market) or to generate a steadier return for investors than tracking the index would achieve. Of course, the fund manager could make the wrong decisions and under-perform the market. And there is no guarantee that an actively managed fund that performs well in one year will continue to do so. Past performance is no guarantee of future returns.
Trackers do not beat or under-perform the market (except as already noted), but they are not necessarily less risky than actively managed funds invested in the same asset class. Open-ended investment funds and investment trusts can both be trackers.