If traders are positive on the prospects for the Yen, they would expect the number on the right to go down – i.e. the Yen would be getting stronger against the Dollar. Traders would be buying less Yen with a Dollar as the Yen got stronger. Similarly, if the Yen was expected to weaken, forex traders would expect the Yen number to go up, reflecting the fact that the dollar could buy more yen.
Depicted as yellow/orange/red bars, the impact is a basic indicator of the potential move a data release might trigger on currencies. Shall a bar be red and long, market observers expect this data to have great probability to move the Forex market. Shall this bar be yellow and short, the probability is viewed as low. In orange, we’re just in between.

Trading foreign exchange on margin carries a high level of risk and may not be suitable for all investors. The high degree of leverage can work against you as well as for you. Before deciding to trade foreign exchange you should carefully consider your investment objectives, level of experience and risk appetite. The possibility exists that you could sustain a loss of some or all of your initial 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.