What do overbought and oversold mean?

Risk Warning : Trading CFDS on margin carries a high level of risk, and may not be suitable for all investors. Before deciding to trade foreign exchange, you should carefully consider your investment objectives, level of experience, and risk appetite. There is a possibility that you may sustain a loss of some or all of your investment and therefore you should not invest money that you cannot afford to lose. You should be aware of all the risks associated with foreign exchange trading, and seek advice from an independent financial advisor if you have any doubts.