About this app

Herfindahl index over portfolio weights, whose reciprocal is the number of equally weighted positions carrying the same concentration, alongside top-three share and a Gini coefficient on the weights, drawn as a donut. Twelve holdings where three are 70% of the book resolve to an effective count near three. States that concentration is a legitimate way to invest but is not diversification, and that equal weights across correlated names give an effective count of one regardless of what this number says.