In search of a truly rational investment approach

John Maynard Keynes once said: "There is nothing so dangerous as the pursuit of a rational investment policy in an irrational world." Keynes certainly had memorable thoughts on the subject of rationality in investing, but were they more quotable than wise? Here, Keynes seems to suggest that investors should pursue an irrational investment policy. Much of this debate, however, depends on what you mean by 'rational'. Traditional investment policies – though widely considered rational – frequently ignore liquidity requirements and assume every investor has the ability to stick with th...