Private placement fund refers to a fund product that collects funds from specific investors, institutions or individuals in a non-public way and conducts investment and financial management according to the return agreed by investors and managers. Private equity funds invest in a wide range of objects, from securities products to financial derivatives to corporate equity, from money market to capital market to industrial market, from spot market to futures market, from domestic market to international market. Private equity investment fund refers to equity investment in unlisted enterprises with financing intentions through private placement. In the process of transaction implementation, the future exit mechanism is considered, that is, through listing, mergers and acquisitions or management buyback, the shares are sold for profit. According to the different stages of private equity investment in enterprises, private equity investment can be divided into venture capital, development capital, merger and acquisition funds and PIPE (post-listing private equity investment), or into seed or early-stage funds, growth funds and restructuring funds. According to the different objects of private equity investment, private equity investment can be divided into venture capital fund, infrastructure investment fund, pillar industry investment fund and enterprise restructuring investment fund.