The histogram below shows the daily percentage moves of VXX for 2010. If you plot this distribution for a normal stock or ETF you will get a normal looking distribution, with an average close to zero. This distribution (the red line marks zero), is asymmetrical (fat tail on the positive side), with an overall average of minus 0.43%. In contrast, the average of VIX’s percentage moves in 2010 was plus 0.20%. Since VXX on average has a negative percentage move, this drives VelocityShares XIV in the positive direction.