Securities proprietary business contains four meanings: ① Only securities companies that have been approved by China Securities Regulatory Commission to engage in securities proprietary business can engage in securities proprietary business; (2) Self-operated business is a kind of business behavior of securities companies, aiming at profit, buying and selling securities for themselves and making profits through the bid-ask spread; (3) Securities companies engaged in proprietary business must use their own funds that can be used for proprietary business or funds raised according to law; ④ Proprietary trading must be conducted in a securities account opened in its own name, and only other securities publicly issued according to law or recognized by China Securities Regulatory Commission can be traded.