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 bearing an international equity portfolio needs to purchase and sell several pairs of foreign currencies to pay for foreign securities purchases.
The foreign exchange market is the most liquid financial market in the world. Traders include governments and central banks, commercial banks, other institutional investors and financial institutions, currency speculators, other commercial corporations, and individuals. According to the 2019 Triennial Central Bank Survey, coordinated by the Bank for International Settlements, average daily turnover was $6.6 trillion in April 2019 (compared to $1.9 trillion in 2004). Of this $6.6 trillion, $2 trillion was spot transactions and $4.6 trillion was traded in outright forwards, swaps, and other derivatives.
Unlike stock markets, which can trace their roots back centuries, the forex market as we understand it today is a truly new market. Of course, in its most basic sense—that of people converting one currency to another for financial advantage—forex has been around since nations began minting currencies. But the modern forex markets are a modern invention. After the accord at Bretton Woods in 1971, more major currencies were allowed to float freely against one another. The values of individual currencies vary, which has given rise to the need for foreign exchange services and trading.