What is SPAN and exposure margin?
SPAN Margin is the minimum requisite margins blocked for futures and option writing positions as per the exchange’s mandate.
The ‘Exposure Margin’ is the margin blocked over and above the SPAN to cushion for any MTM losses.
Both the SPAN and Exposure margins are specified by the exchange. So at the time of initiating a futures trade, the client has to adhere to the initial margin requirement. The entire initial margin (SPAN + Exposure) is blocked by the exchange.
You can use the margin calculator to fine out the SPAN & Exposure margin required for a futures position or short option.
Note: From 2nd July 2018 onwards, SEBI has made it mandatory for both SPAN and exposure margin to be blocked in order to take an overnight position. If not, margin penalty will be applicable. Click here for the circular from SEBI.
You can read this post on TradingQ&A for more information.