The common gap is the most frequent type of stock gap. They occur in markets without a stron trend. Common gaps occur within the normal course of trading and are insignificant developments in terms of price action. Common gaps are minor in size, occur often, and are not accompanied by high volume. Common gaps tend to fill soon after they are formed.They are also referred to as a trading gap or an area gap, the common gap is usually uneventful. In fact, they can be caused by a stock going ex-dividend when the trading volume is low. These gaps are common (get it?) and usually get filled fairly quickly.