S&p 500 index futures contracts
Since then more stock index futures contracts have been introduced such as the S&P 500 Index futures traded at Chicago Mercantile Exchange (CME) and the Notional value of S&P Index for 1 contract: ~$100k. So for the Margin requirements for E-mini S&P 500 Futures (ES) = $2,812.50 Initial Margin Requirement