As we have seen, the speculative phase of the craze frequently con.. stitutes a sufficient condition for the occurrence of a panic.1 For instance, as prices spiral giddily in a boom, apprehension increases among stock holders. A critical event, perhaps a rumor that a big holder is selling out, crystallizes this anxiety and triggers a dash for funds. In many cases the leaders of the boom try to stem the collapse; but once a panic has started, stabilizing the market is difficult.2