Private placement fund refers to a securities investment fund that raises funds from specific investors in a non-public way and invests in securities. Private equity funds are raised by means other than mass communication, and promoters set up investment funds to invest in securities by collecting funds from non-public multi-subjects.

Private placement fund refers to a fund raised privately or directly from a specific group. The corresponding public offering fund (public offering

Fund) is a fund raised from the public. People usually say that funds are mainly mutual funds, that is, securities investment funds.

Divided from the research paradigm, there are three main analysis methods of securities investment: basic analysis, technical analysis and evolution analysis. These three analytical methods are based on completely different theoretical systems and logical structures, and their main research objects only focus on a specific aspect or category of market operation, all of which have their rationality and limitations, but they are essential for comprehensively understanding and deeply exploring the laws of market operation. They depend on different theoretical bases, premises and paradigm characteristics, which are interrelated and have important differences in practical application. Among them, basic analysis belongs to general economic paradigm, technical analysis belongs to mathematics or Newton paradigm, and evolutionary analysis belongs to biology or Darwin paradigm.