Factors like interest rates, trade flows, tourism, economic strength and geopolitical risk affect supply and demand for currencies, which creates daily volatility in the forex markets. An opportunity exists to profit from changes that may increase or reduce one currency's value compared to another. A forecast that one currency will weaken is essentially the same as assuming that the other currency in the pair will strengthen because currencies are traded as pairs.

Imagine a trader who expects interest rates to rise in the U.S. compared to Australia while the exchange rate between the two currencies (AUD/USD) is .71 (it takes $.71 USD to buy $1.00 AUD). The trader believes higher interest rates in the U.S. will increase demand for USD, and therefore the AUD/USD exchange rate will fall because it will require fewer, stronger USD to buy an AUD.
Experts say that forex is a zero-sum game. That means that someone always loses commensurate to someone else’s win — that’s how the game is played. When you add in costs and fees associated with running a forex account and making trades, you enter negative-sum territory. That said, shrewd trading moves can pay out. Substantially. If you have the time and interest required to learn to identify patterns in price fluctuations and execute far-sighted trades, you will make wins on the forex market. That said, the most thoughtful strategy is also liable to bring about loss. Don’t trade more than you can afford to lose.
Individual retail speculative traders constitute a growing segment of this market. Currently, they participate indirectly through brokers or banks. Retail brokers, while largely controlled and regulated in the US by the Commodity Futures Trading Commission and National Futures Association, have previously been subjected to periodic foreign exchange fraud.[63][64] To deal with the issue, in 2010 the NFA required its members that deal in the Forex markets to register as such (I.e., Forex CTA instead of a CTA). Those NFA members that would traditionally be subject to minimum net capital requirements, FCMs and IBs, are subject to greater minimum net capital requirements if they deal in Forex. A number of the foreign exchange brokers operate from the UK under Financial Services Authority regulations where foreign exchange trading using margin is part of the wider over-the-counter derivatives trading industry that includes contracts for difference and financial spread betting.
In the context of the foreign exchange market, traders liquidate their positions in various currencies to take up positions in safe-haven currencies, such as the US dollar.[85] Sometimes, the choice of a safe haven currency is more of a choice based on prevailing sentiments rather than one of economic statistics. An example would be the financial crisis of 2008. The value of equities across the world fell while the US dollar strengthened (see Fig.1). This happened despite the strong focus of the crisis in the US.[86]

Foreign exchange trading increased by 20% between April 2007 and April 2010 and has more than doubled since 2004.[58] The increase in turnover is due to a number of factors: the growing importance of foreign exchange as an asset class, the increased trading activity of high-frequency traders, and the emergence of retail investors as an important market segment. The growth of electronic execution and the diverse selection of execution venues has lowered transaction costs, increased market liquidity, and attracted greater participation from many customer types. In particular, electronic trading via online portals has made it easier for retail traders to trade in the foreign exchange market. By 2010, retail trading was estimated to account for up to 10% of spot turnover, or $150 billion per day (see below: Retail foreign exchange traders).

The last hour of trading (usually in London sessions) might often tell the truth about how strong a trend truly is. Smart money usually shows its face during the last hour, continuing to mark positions in its favour. As long as a market has consecutive strong closes, look for the trend to continue. The uptrend is most likely to end when there is a morning rally first, followed by a weak close, and vice versa for a short trend.
For instance, if you opened a long trade on the GBP/USD currency pair, and the pair increased in value, the price limit at which the trade should close (the stop loss) would climb alongside the price of the currency pair. If the value of the GBP/USD then started to fall, the trade would be closed as soon as it hit your stop loss, preserving any profits you had made beforehand.
In the futures market, futures contracts are bought and sold based upon a standard size and settlement date on public commodities markets, such as the Chicago Mercantile Exchange. In the U.S., the National Futures Association regulates the futures market. Futures contracts have specific details, including the number of units being traded, delivery and settlement dates, and minimum price increments that cannot be customized. The exchange acts as a counterpart to the trader, providing clearance and settlement.