This thing called transparency is spreading in thecorporate-bond market, and it's hurting traders' bottom lines.

Credit traders are increasingly being forced to publish theprices at which they bought and sold securities. They're reapingsmaller profits as a result, so it's no wonder they're negative onnew proposals requiring them to report details on an even broaderswath of debt trades.

In the U.S., the Financial Industry Regulatory Authority (FINRA)will start disseminating prices on privately sold corporate debt atthe end of this month. While the U.S. has required some publicdisclosure of corporate-bond prices since 2002, the EuropeanParliament just approved a similar set of rules in April, which theEuropean Securities & Markets Authority now has the task ofdefining.