In contrast to the other two psychological causes, speculative contagion has a natural end. A speculative bubble, sustaining itself solely by reaction to price increases, cannot go on forever.
其他两个心理原因构成鲜明对比的是，投机热会像生物一般有寿终正寝的一天。投机泡沫仅靠对价格上涨作出反应来维系自己的生命，因此它不会永远存活下去。