banknifty weightage

[sachin928111]

how the weightage of banknifty or nifty is decided is it fixed percentage decided by exchange or does it changes with the marketcap of companies.how the weight of a company is decided in index. one formulae could be

companys market cap*100
----------------------------------------------
total market cp of all the company in the index
if this is not then what is that logic

 

[Loss_Lover]

how the weightage of banknifty or nifty is decided is it fixed percentage decided by exchange or does it changes with the marketcap of companies.how the weight of a company is decided in index. one formulae could be

companys market cap*100
----------------------------------------------
total market cp of all the company in the index
if this is not then what is that logic

If it is for academic purposes, then go through these documents:
Nifty50 Index: Go to page 11 of this pdf.
Nifty Sectoral Index (like BankNifty): Go to page 9 of this pdf.

Otherwise, in real practical life for trading purposes, being, retail traders we won't be able to get all the required accurate data-points. So, you have to take an alternate route if you want to formulate your own indices based customized-analysis:
1. Calculating multiple-security statistics with AddToComposite function
2. Introduction to AddToComposite by Herman van den Bergen