Investment management firms

Investment management firms (who typically manage large accounts on behalf of customers such as pension funds and endowments) use the foreign exchange market to facilitate transactions in foreign securities. For example, an investment manager with an international equity portfolio will need to buy and sell foreign currencies in the spot market in order to pay for purchases of foreign equities. Since the forex transactions are secondary to the actual investment decision, they are not seen as speculative or aimed at profit-maximization.
Some investment management firms also have more speculative specialist currency overlay operations, which manage clients' currency exposures with the aim of generating profits as well as limiting risk. Whilst the number of this type of specialist firms is quite small, many have a large value of assets under management (AUM), and hence can generate large trades.