You short sell 100 shares of TOTOFoot at a price of $15 per share. Knowing that the minimum margin is 20% and you have $700 in cash, calculate the initial margin and determine the price that would trigger a margin call from your broker? If the price of TOTOFoot goes from $15 to $30, what is the return on your investment if you have given your broker $700 as collateral and each share pays a dividend of $0.90?