Prudent-Man Rule

Prudent-man rule

A common law standard against which those investing the money of others fiduciaries are judged.

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Prudent Man Rule

A legal rule requiring investment advisers to only make investments for their clients' discretionary accounts that a "prudent person" would make. This means that investment advisers operating discretionary accounts are not allowed to make investments they believe will lose money for the client. It does not require that the investment adviser always make correct decisions; it merely requires him/her to make decisions that will be generally accepted as sound for someone of average intelligence. The rule has its origins in an 1830 court decision in Massachusetts, stating that trustees must manage the affairs of others as if they were managing "their own affairs." See also: Suitability rules, Twisting.