An equally weighted price index of all the stocks covered in The Value Line Investment Survey. Geometric refers to the geometric averaging technique that is used to compute the average, which is the nth root of the product of a set number of terms. For example, if there are 3 terms, then the geometric average of the 3 numbers would be the third root of the product of the 3 numbers. Geometric indices are not commonly used. The index is watched as a proxy for the marketÂ’s performance and represents the typical retail investorÂ’s portfolio. Institutional investors like it because it is an indicator of how mid-cap stocks are performing.