"There is a very high degree of risk involved in trading securities. With respect to margin-based foreign exchange trading, off-exchange derivatives, and cryptocurrencies, there is considerable exposure to risk, including but not limited to, leverage, creditworthiness, limited regulatory protection and market volatility that may substantially affect the price, or liquidity of a currency or related instrument. It should not be assumed that the methods, techniques, or indicators presented in these products will be profitable, or that they will not result in losses." Learn more.
All exchange rates are susceptible to political instability and anticipations about the new ruling party. Political upheaval and instability can have a negative impact on a nation's economy. For example, destabilization of coalition governments in Pakistan and Thailand can negatively affect the value of their currencies. Similarly, in a country experiencing financial difficulties, the rise of a political faction that is perceived to be fiscally responsible can have the opposite effect. Also, events in one country in a region may spur positive/negative interest in a neighboring country and, in the process, affect its currency.
Just like stocks, you can trade currency based on what you think its value is (or where it's headed). But the big difference with forex is that you can trade up or down just as easily. If you think a currency will increase in value, you can buy it. If you think it will decrease, you can sell it. With a market this large, finding a buyer when you're selling and a seller when you're buying is much easier than in in other markets. Maybe you hear on the news that China is devaluing its currency to draw more foreign business into its country. If you think that trend will continue, you could make a forex trade by selling the Chinese currency against another currency, say, the US dollar. The more the Chinese currency devalues against the US dollar, the higher your profits. If the Chinese currency increases in value while you have your sell position open, then your losses increase and you want to get out of the trade.
You may have noticed that the value of currencies goes up and down every day. What most people don't realize is that there is a foreign exchange market - or 'Forex' for short - where you can potentially profit from the movement of these currencies. The best known example is George Soros who made a billion dollars in a day by trading currencies. Be aware, however, that currency trading involves significant risk and individuals can lose a substantial part of their investment. As technologies have improved, the Forex market has become more accessible resulting in an unprecedented growth in online trading. One of the great things about trading currencies now is that you no longer have to be a big money manager to trade this market; traders and investors like you and I can trade this market.

The need to exchange currencies is the primary reason why the forex market is the largest, most liquid financial market in the world. It dwarfs other markets in size, even the stock market, with an average traded value of around U.S. $2,000 billion per day. (The total volume changes all the time, but as of August 2012, the Bank for International Settlements (BIS) reported that the forex market traded in excess of U.S. $4.9 trillion per day.)