Some traders find opportunities to trade by looking at fundamental indications of economic health. For example, supply and demand for a currency decide the price and liquidity, so traders keep an eye on the central bank’s interest rates to see which way the market might move. If a currency has a high interest rate, it might be profitable to invest for the interest alone; however, the reason for the high interest rate might be economic instability. All market participants trade based on their information and expectations.