Since 90% confidence isn’t enough, the 10% confidence that it isn’t so will have to do, eh? ;’)
The laymen usually misunderstand how little “90%” is as a confidence level - and some traders with fear masterfully abuse this ignorance. 90% vs 10% is not that “qualitatively” far from 50% vs 50% - and one can transform one to the other by a “slight” pressure in the methodology and the formulae. If you want to be scientifically confident about a conclusion, you should really demand 99.9% or more. And it’s actually not that hard to obtain such stronger evidence assuming that your hypothesis is actually correct and the “signal” exists.
http://motls.blogspot.com/2010/03/defending-statistical-methods.html