Morgan Stanley's profit beat Wall Street estimates in the second quarter as its traders cashed in on volatile markets, but shares fell since the market opening as its investment banking revenue shrank.

Shares of Goldman Sachs and Morgan Stanley fell Wednesday despite stronger-than-expected profit from the two big banks, as investors saw little reason to bid up equity prices further after gains in recent weeks.

Another three megabanks are due to report second-quarter earnings on Wednesday, shedding light on the health of dealmaking, sales and trading, and consumer activity. Bank of America, Morgan Stanley, and Goldman Sachs—the second-,