Potential conflicts of interest may arise between different parts of a bank, creating the potential for financial movements that could be deemed as market manipulation. Authorities that regulate investment banking (the FSA in the United Kingdom and the SEC in the U.S.) require that banks impose a Chinese Wall which prohibits communication between Investment Banking and Research and Equities.

Some of the conflicts of interest involved in investment banking are:

Historically, equity research firms were founded and owned by investment banks. One common practice is for equity analysts to initiate coverage on a company in order to develop relationships that lead to highly profitable investment banking business. In the 1990s, many researchers allegedly traded positive stock ratings directly for investment banking business. Companies would also threaten to divert investment banking business to competitors unless their stock was rated favorably. Increased pressure from regulators and a series of lawsuits and prosecutions curbed this business to a large extent following the 2001 stock market tumble.

Many investment banks also own retail brokerages. Also during the 1990s, some retail brokerages sold consumers securities that did not meet their stated risk profile. This behavior may have led to investment banking business or even sales of surplus shares during a public offering to keep public perception of the stock favorable.

Since investment banks engage heavily in trading for their own account, there is always the temptation or possibility that they might engage in front running.