Is margin trading good or bad? Margin trading, as a common trading method in most securities markets in the world, has four functions: First, margin trading can integrate more information into securities prices and provide trading activities in the opposite direction for the market. When investors think that the stock price is too high or too low, they can promote the stock price to be reasonable by means of financing buying and selling, which is helpful to the formation of price stability mechanism in the market. Second, margin financing and securities lending can enlarge the supply and demand of funds and securities to a certain extent, increase the trading volume of the market, thus activating the securities market and increasing its liquidity. Third, margin trading can provide investors with new trading methods, change the unilateralism of the securities market and become a tool for investors to avoid market risks. Fourth, margin financing and securities lending can broaden the business scope of securities companies, to a certain extent, increase the channels for the use of their own funds and securities, and increase the allocation of other funds and securities financing after circulation, thus improving the efficiency of the use of financial assets.