Interesting comparison with Bank Nifty
Here is Bank Nifty top 5 and their % weights
Bank Nifty
- HDFC Bank Ltd. 35.2%
- ICICI Bank Ltd. 18.5%
- Kotak Mahindra Bank Ltd. 13.2%
- Axis Bank Ltd. 10.1%
- State Bank of India 8.7%
Top stock is 35% of it. Top 2 which are very correlated is 53%. Top 3, again highly correlated are 66%. I need to be really out of my mind to call this an index. This is betting on HDFC for all practical purposes 
I heard SEBI is going to restrict the weightage of one stock in an index to 25%. So may be soon, this is will somewhat be an index. May be
Nifty
- HDFC Bank Ltd. 10.3%
- Reliance Industries Ltd. 9.7%
- Housing Development Finance Corporation 7.3%
- Infosys Ltd. 6.6%
- I T C Ltd. 5.5%
