Gaps primarily occur over the weekend because it is the only time the forex market closes. Gaps may also occur on very short timeframes such as a one-minute chart or immediately following a major news announcement. A gap is a change in price levels between the close and open of two consecutive days. Although most technical analysis manuals define the four types of gap patterns as Common, Breakaway, Continuation, and Exhaustion, those labels are applied after the chart pattern is established.