"Doubles up" is very common amongst the people who bet especially in casinos. Imagine when a trader does his or her analysis but price moves in opposite direction If the trader is confident enough that this is only a short-term move and price will go back as the analysis he or she may double the current position in an asset. Generally, after an adverse price movement event, there is a high chance to open another position at a better price. You have to be careful, though as this will increase the risk.
