The index value of a smallcase indicates the absolute price returns of that particular smallcase from the date of its inception. The index value is set to 100 on the inception date of the smallcase. 

The current index value shows by how much it has gone up since then. For example, the index value 158.11 indicates that the smallcase has given a total return of 58.11% since inception. You can also view the daily increase or decrease in the index value.

For the smallcases in the Discover section (the ones you haven't bought), the index values are updated on an hourly basis

To maintain accuracy, the index values of the smallcases in your investments (the ones you have bought), are updated on a real time basis