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.[60] 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”.[61] Central banks also participate in the foreign exchange market to align currencies to their economic needs.
Forex day trading is usually used in order to eliminate the need to pay fees for keeping a position overnight. These fees are referred to as 'Swaps'. In some cases, the swaps could be positive, and a trading strategy based on acquiring assets with positive swaps is referred to as a 'Carry Trade', however this strategy is beyond the scope of this article. Day traders hold a lot of importance for the Forex market.
Forex trading is governed by the National Futures Association, and they routinely check brokerages for financial irregularities, hidden or overly high fees, and scams. A key point of comparison between forex brokerages is their regulatory approval status with the NFA. Because the forex market and its major players move rapidly, it’s wise to regularly check on that status via the NFA’s Status Information Center. Increased regulation (coupled with higher capital requirements) continue to force forex brokers to leave the playing field, and one side effect is that it’s increasingly easy to find the best out of a constrained number of options.

Forex is a portmanteau of foreign currency and exchange. Foreign exchange is the process of changing one currency into another currency for a variety of reasons, usually for commerce, trading, or tourism. According to a recent triennial report from the Bank for International Settlements (a global bank for national central banks), the average was more than $5.1 trillion in daily forex trading volume.