The idea is a challenge to basic Bogle indexation, and it has gathered billions in exchange-traded fund and institutional assets. Worse, if you leave enough graduate students alone with computers and demand a thesis topic, they are likely to discover something no one has ever seen before, even if it isn't there. From very basic factors - such as small-cap versus large-cap, or traditional value investing - researchers have now ferreted out multitudes of factors that are supposed to give portfolios new zip. [...] the record goes to two other researchers who found 600 factors named in research literature. Come up just a smidge short of statistical significance, however, and you disappear as though your work never existed. First seen in medicine Researcher John P.A.