In the final stages of a long-running investigation into corruption in the world’s largest financial market, federal prosecutors have recently informed Barclays, JPMorgan Chase, the Royal Bank of Scotland and Citigroup that they must enter guilty pleas to settle the cases, the newspaper reported. The pleas would be likely to carry a symbolic stigma, if limited actual fallout, in handing felony convictions to some of the world’s biggest banks, the newspaper said. Representatives of Citigroup, JP Morgan, RBS and Barclays did not respond to emails seeking comment on the report.