Right, but what is the purpose of statistics like this? The purpose is for them to inform our understanding of what might happen in the future. As mentioned above, since market movements follow a power law rather than normal distribution, the average gives us absolutely no information about what might happen. Thus this statistic fails at the goal of having a purpose; it is just a meaningless number, like those meme baseball statistics about who is the third-best thrower of fastballs on a rainy friday or whatever.