Once Nixon abolished the gold standard, the dollar's value quickly plummeted. The dollar index was established to give companies the ability to hedge this risk. Someone created the U.S. Dollar Index to give them a tradeable platform. Soon, banks, hedge funds, and some speculative traders entered the market. They were more interested in chasing profit than in hedging risks. 

Unlike a stock market, the foreign exchange market is divided into levels of access. At the top is the interbank foreign exchange market, which is made up of the largest commercial banks and securities dealers. Within the interbank market, spreads, which are the difference between the bid and ask prices, are razor sharp and not known to players outside the inner circle. The difference between the bid and ask prices widens (for example from 0 to 1 pip to 1–2 pips for currencies such as the EUR) as you go down the levels of access. This is due to volume. If a trader can guarantee large numbers of transactions for large amounts, they can demand a smaller difference between the bid and ask price, which is referred to as a better spread. The levels of access that make up the foreign exchange market are determined by the size of the "line" (the amount of money with which they are trading). The top-tier interbank market accounts for 51% of all transactions.[63] From there, smaller banks, followed by large multi-national corporations (which need to hedge risk and pay employees in different countries), large hedge funds, and even some of the retail market makers. According to Galati and Melvin, “Pension funds, insurance companies, mutual funds, and other institutional investors have played an increasingly important role in financial markets in general, and in FX markets in particular, since the early 2000s.” (2004) In addition, he notes, “Hedge funds have grown markedly over the 2001–2004 period in terms of both number and overall size”.[64] Central banks also participate in the foreign exchange market to align currencies to their economic needs.
Unlike stocks, forex trades have low, if any, commissions and fees. Even so, new forex traders are always advised to take a conservative approach and use orders, like stop-loss, to minimize losses. High leverage, which should be prudently applied, gives traders the opportunity to achieve dramatic results with far less capital than necessary for other markets. Forex trading requires training and strategy, but can be a profitable field for individuals looking for a lower risk endeavor. Learning currency trading gives traders a range of exciting new opportunities to invest in.
These cover the bulk of countries outside Europe. Forex brokers catering for India, Hong Kong, Qatar etc are likely to have regulation in one of the above, rather than every country they support. Some brands are regulated across the globe (one is even regulated in 5 continents). Some bodies issue licenses, and others have a register of legal firms.

Both types of contracts are binding and are typically settled for cash for the exchange in question upon expiry, although contracts can also be bought and sold before they expire. The forwards and futures markets can offer protection against risk when trading currencies. Usually, big international corporations use these markets in order to hedge against future exchange rate fluctuations, but speculators take part in these markets as well.

There are actually three ways that institutions, corporations and individuals trade forex: the spot market, the forwards market and the futures market. The forex trading in the spot market always has been the largest market because it is the "underlying" real asset that the forwards and futures markets are based on. In the past, the futures market was the most popular venue for traders because it was available to individual investors for a longer period of time. However, with the advent of electronic trading and numerous forex brokers, the spot market has witnessed a huge surge in activity and now surpasses the futures market as the preferred trading market for individual investors and speculators. When people refer to the forex market, they usually are referring to the spot market. The forwards and futures markets tend to be more popular with companies that need to hedge their foreign exchange risks out to a specific date in the future.