Zero-Based Trading is a type of speculation based on trading strategies that focuses on market trends and price changes to make a profit by establishing multiple trading orders. In the case of big short selling, investors would buy and sell stocks, futures, foreign exchange and other financial products to obtain the difference in profit when the market fluctuated greatly. Under normal circumstances, investors would open multiple accounts at the same time to buy and sell in different markets through different accounts to expand their profits. However, there were risks in selling short. Because investors cannot accurately predict market trends and price movements, they may trade in the wrong direction and lose money. In addition, big short selling could easily attract the attention of the regulator because it was suspected of violating market rules and regulations. Big short selling was a high-risk and high-profit speculation. It required investors to have a certain market analysis ability and trading strategy. At the same time, they had to pay close attention to market trends and risk changes to avoid unnecessary losses.