There are hundreds of investment theories out there that are misguided, unrealistic or completely wrong-headed. Of these, only a few are so seductive that great numbers of people take them up. Chief among these is the “efficient market hypothesis.”

The conglomerate sector was down 8.85% for the first quarter of 2008. That might not seem like an argument in favor of conglomerate investing, but when you consider that the Standard & Poor’s 500 Index was down 10.05% for the same period it seems a bit better.