"Buy the rumor, sell the fact": This market truism can apply to many currency situations. It is the tendency for the price of a currency to reflect the impact of a particular action before it occurs and, when the anticipated event comes to pass, react in exactly the opposite direction. This may also be referred to as a market being "oversold" or "overbought". To buy the rumor or sell the fact can also be an example of the cognitive bias known as anchoring, when investors focus too much on the relevance of outside events to currency prices.
A single pound on Monday could get you 1.19 euros. On Tuesday, 1.20 euros. This tiny change may not seem like a big deal. But think of it on a bigger scale. A large international company may need to pay overseas employees. Imagine what that could do to the bottom line if, like in the example above, simply exchanging one currency for another costs you more depending on when you do it? These few pennies add up quickly. In both cases, you—as a traveler or a business owner—may want to hold your money until the forex exchange rate is more favorable.
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.
These currency pairs, in addition to a variety of other combinations, account for over 95% of all speculative trading in the forex market. However, you will probably have noticed the US dollar is prevalent in the major currency pairings. This is because it’s the world’s leading reserve currency, playing a part in approximately 88% of currency trades.
Big news comes in and then the market starts to spike or plummets rapidly. At this point it may be tempting to jump on the easy-money train, however, doing so without a disciplined trading plan behind you can be just as damaging as gambling before the news comes out. This is because illiquidity and sharp price movements mean a trade can quickly translate into significant losses as large swings take place or ‘whipsaw’.
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.