The margin requirements on the S&P 500 futures contract are 10%. If one sells the contract at 2,075, and each contract has a multiplier of 250, how much margin must be put up for each contract sold? If the futures price falls by 2% from the level of 2,075 what will happen to margin account of the investor who holds one contract? What will be the investors percentage return (gain or loss) based on the amount put up as margin?