Margin trading is a stock trading method, which allows investors to borrow money to buy stocks without holding enough stocks, or borrow money to sell stocks without holding enough funds. Margin trading requires investors to provide a certain amount of collateral, usually stocks or cash. Stock index futures is a kind of financial derivatives, which allows investors to buy or sell stock indexes at an agreed price at a certain point in the future to hedge the risks brought by market fluctuations or speculate. Stock index futures is a high-risk and high-yield trading method, which requires investors to have enough professional knowledge and skills to take higher risks.