The main force's position building operation is the preliminary foundation for operating a stock, which needs to be established in a relatively stable policy environment, but at the same time, it also needs to be established in a market environment where the overall market has fallen significantly and investors are still in a panic or indecisive state. Such a market environment is most suitable for the main force's capital to build positions. There are several key points here. Firstly, a stable and positive policy environment is needed to complement it. A stable and positive policy environment can effectively block the space for a significant decline in the market and provide policy support for the main players to go long in the future. Secondly, after a long period of significant decline in the overall market and individual stocks, the risks have almost been released. With the continuous decline of the index, the investment value of individual stocks has gradually been reflected. At this time, some forward thinking main players will start to enter and build positions. The third is to choose a time when the overall market and individual stock sentiment are pessimistic and sluggish to build a position. Due to the large size of the main capital, it is impossible to complete the position building within one day or one or two months, and there are also different orders for the main capital to enter the market. Therefore, from the entry of the main capital to the end of the position building, the main capital will use all available means to cause significant fluctuations in the stock index, in order to achieve the main capital's position building goal. This is the reason why investors often see the policy of resolutely going long near the bottom of the market, resulting in significant fluctuations in the stock index. Figure 1 shows the trend of building positions in the Shanghai Composite Index from June 2005 to March 2006.

The techniques used by the main force in building positions can usually be divided into five types. One is wave style (i.e. oscillation style) building, which is a way for the main force to use the psychology of some retail investors who are afraid of rising and not afraid of falling, while others are afraid of falling and not afraid of rising, to force some retail investors to sell both rising and falling in a volatile buying behavior. As shown in Figures 2 and 3;