It has long been part of folklore among bond dealers that the “repo” market for US Treasury paper is the last outpost of the “wild west”, where traders can still get away with market manipulation unchecked. Now, however, the sheriff is in town.

US regulators are investigating trading practices in the Treasury bond market and, in the process, are bringing to light such arcane and nefarious practices as “Treasury squeezes” and “slamming the wire”.