A gap in a chart is an empty space between a trading period and he following trading period. This occurs when there is a large difference in price between two sequential trading periods. If the trading range in one period is between 50 taka and 65 taka and the next trading period opens at 70 Taka there will be a large gap on the chart between these two periods. look at the chart first one downward gap. when the price of a particular share starts below than yesterdays price then there is a downward gap. in this situation 80% share’s price increase. Upward Gap is just reverse of Downward Trend and in case of Upward Tren 80% share’s price falls. - See more at: http://stocks-basics.blogspot.com/2016/11/gaps.html#sthash.fos7PaXz.dpuf