non normality of asset returns are known to finance in the 60s, maybe even earlier. the normal distribution is still used in many cases because it makes problem

non normality of asset returns are known to finance in the 60s, maybe even earlier. the normal distribution is still used in many cases because it makes problems solvable. in any case I wonder how much of these price aberrations are caused by bad statistics and not exuberance, overconfidence, or system failures. the latter things can't really be captured by math.