Gann Theory is a unique analysis method and market measurement theory established by investment guru William D. Gann through the comprehensive application of mathematics, geometry, religion, and astronomy, combined with his own experience in stocks and futures Proposed by outstanding achievements and valuable experience in the market, including Gann's time rule, Gann's price rule and Gann's line, etc.

The Gann theory believes that there are natural rules in the universe in the stock and foreign exchange markets. The price trend of the market is not chaotic, but can be predicted through mathematical methods. Its essence is to establish a strict trading order in the seemingly disorderly market, which can be used to discover when the price will retrace and what price it will retrace to.

1. Excessive buying and selling with limited capital. That is to say, operations are too frequent. Short-term and ultra-short-term operations in the market require high operating skills. Before investors master these operating skills, over-emphasis on short-term operations will often lead to considerable losses.

2. Investors did not set up stop-loss points to control losses. Many investors suffered huge losses because they did not set a suitable stop loss point. As a result, their mistakes were allowed to develop indefinitely, and their losses became larger and larger. Therefore, learning to set stop loss points to control risks is one of the basic skills that investors must learn. There are also some investors, even some market veterans, who set stop loss points but did not resolutely implement them in actual operations. As a result, they suffered huge losses due to a mistake.

3. Lack of market knowledge is the most important reason for losses in market trading. Some investors do not pay attention to learning market knowledge, but take things for granted or subjectively believe what the market is like. They cannot distinguish the authenticity of the news. As a result, they accept mistakes and misleads and suffer huge losses. There are also some investors who only rely on some knowledge learned in books to guide practice and apply it indiscriminately, causing huge losses. Gann emphasizes market knowledge and practical experience. And this kind of market knowledge often takes a long time to experience in the market before you can truly understand it.