(n) (US) a theory according to which one is justified to buy overpriced shares as there is always a bigger fool who will rebuy them even at a higher price - teoria, według której można kupić akcje po zbyt wygórowanej cenie, ponieważ zawsze znajdzie się jakiś naiwniak, który je odkupi po jeszcze wyższej cenie
I may be talking out of turn, but I believe that according to the bigger fool theory I will always be able to sell this share even at a more exaggerated price.