So an individual investor has to be really right to rationalize doing it, says Mark Kritzman, who helps oversee more than $25 billion at Windham Capital Management in Cambridge, Mass.

• 因此，帮助WindhamCapitalManagement负责250多亿美元资产的克里兹曼(MarkKritzman)说，个人投资者的确值得好好判断一下这样做的合理性。