U.S. banks posted stronger-than-expected trading results in the second quarter due to surprisingly active markets in June, but bank executives stopped short of saying the good times would continue. Analysts expected banks’ bond trading revenue to have fallen somewhere around 20 percent in the second quarter from the same period last year. April and May were slow months, with JPMorgan and Citigroup both saying in May that their second quarter trading revenue would drop. The European Central Bank cut interest rates and announced other initiatives to further loosen monetary policy.