Reusing credit card amount again and again

I have credit card with 1+Lac limit. And I also have an option to do trading with that amount and can return same amount to credit card after getting commission. In this process I can use the same limit 20 times i.e. 20lac of in and out transactions in same credit card. Payment which I get back after trade comes to my bank account from where I pay the bill of Credit Card. Is it okay to do the trading like this and paying tax only on comissions? Please help