The history of quantitative trading is the history of stunning success interspersed with disaster. On so-called"Black Monday in October 1987's there was, assuming a normal distri- bution, a standard deviation event. That is an event which has a probability something like over 27 this compares with there being only something like 10 to the power of 160(1/10160 unlikely series of 1080 atoms in the universe not very likely, in other words. Another such 2008. Financial events wiped out LTCM in 1998, and still more failures ensued in 2007 and asset markets are simply not normal, and these'impossible' events(according to some quan titative analysts) demonstrate this as clearly as is possible. and EMH: over one of the consequences