Exactly,no one knows. One of the reason why i like bitcoin,you cannot know who really holds bitcoin and who doesn't hold and how much ever they may hold,atleast people won't interfere in other people's life.And criminals take advantage of this feature,which is causing bitcoin's name to be bad.But who cares because the price increase and so many features were introduced only for the good people ,which is people who use bitcoin on a regular basis don't care if people who have never use bitcoin say that bitcoin is shit.So if Warren Buffet bought it or not,he is an amazing investor,he will make wise decision which is why he is one of the richest and talented people on the planet Earth.