  Artificial stock market simulation based on agent is an important means to
study financial market. Based on the assumption that the investors are composed
of a main fund, small trend and contrarian investors characterized by four
parameters, we simulate and research a kind of financial phenomenon with the
characteristics of pyramid schemes. Our simulation results and theoretical
analysis reveal the relationships between the rate of return of the main fund
and the proportion of the trend investors in all small investors, the small
investors' parameters of taking profit and stopping loss, the order size of the
main fund and the strategies adopted by the main fund. Our work are helpful to
explain the financial phenomenon with the characteristics of pyramid schemes in
financial markets, design trading rules for regulators and develop trading
strategies for investors.
