is a kind of collective investment mode with "benefit * * * and risk * * *". It refers to a collective investment trust system in which the unequal funds of most investors who are uncertain in society are pooled through contracts or companies and by issuing fund bonds to form a certain scale of trust assets, which are distributed by specialized investment institutions according to the principle of asset portfolio, and the gains are shared by investors in proportion to their capital contribution, and they bear corresponding risks.