This event demonstrated that share prices can fall dramatically even though no generally agreed upon definite cause has been found: a thorough search failed to detect "any" 'reasonable' development that might have accounted for the crash. (Note that such events are predicted to occur strictly by randomness, although very rarely.) It seems also to be true more generally that many price movements (beyond those which are predicted to occur 'randomly') are "not" occasioned by new information; a study of the fifty largest one-day share price movements in the United States in the post-war period seems to confirm this.