An investment fund is a fund in which many investors pool their resources and make investments from the larger capital base. Investment funds can be structured in many ways, depending on the laws and regulations in each country. Often they are structured as companies in their own right. An investment fund typically has an investment manager who makes the overall decisions on what the fund should invest in.

Often, investment funds explicitly declare that their investments will be focused on one particular sector of opportunities. For example, an investment fund might bill itself as interested only in the stock markets of Latin America. Another might declare that it is interested only in investing in the Japanese property market.

By pooling their resources in common funds, investors can share in investments taking place on a much larger scale than anything they could possibly participate in individually.

Funds generally announce their percentage gains for the year to allow investors to make judgements about how successfully the funds have been managed. Investors will often want to compare the performance of investment funds to that of the stock market as a whole. Since stock-market tracking investments are fairly simply and involve a low fee overhead, investors will usually want to see greater performance from more specialised funds with higher overheads.