Then you choose the wrong timing to enter, sometimes we are too reckless to observe the situation,when the green had happened for quite some times then there will be recovery, but we always think that the green will keep on green, so some people tends to enter when the price is already at peak, and once the correction happened that person will losing money and need to wait for another bull trend
When it comes to trading timing is everything, a difference of a few months in your investment can be the difference between having losses or having profits, for example those that invested in October of the previous year have huge profits right now, while those that invested in December just two months later are still losing money and they will need to hold for a long time before they see profits.