What’s the impact cost on a trade for Rs. 5 million of the full S&P CNX Nifty?
It is safe to think that the impact cost is 0.1% or so. This means that if S&P CNX Nifty is at 1000, a buy order goes through at 1001 and a sell order gets 999. NSE’s NEAT software has special facilities to enable buying or selling the entire the S&P CNX Nifty at one shot. The impact cost is not something fixed. It changes, depending upon the liquidity of the market. Indeed, the time-series of the S&P CNX Nifty impact cost is one of the best measures of changes in market liquidity over the years.