Self-regulatory organizations in the U.S. are warning market players about trying to manipulate markets by spreading false rumours and other sorts of abusive activity.

The Financial Industry Regulatory Authority, NYSE Regulation, Inc., and participants of the Options Regulatory Surveillance Authority, say they are coordinating efforts to heighten the monitoring and investigation of trading activity in issuers that may be subject to credit market-related volatility.

The SROs note that there are prohibitions in the rules of both FINRA and the NYSE against the circulation of sensational rumours “that might reasonably be expected to affect market conditions”. They also remind firms of their obligations to “refrain from any conduct or activity inconsistent with just and equitable principles of trade”, and the prohibition on trading on material, non-public information.

“Market participants should be especially aware that intentionally spreading false rumors or engaging in collusive activity to impact the financial condition of an issuer will not be tolerated and will be vigorously and aggressively investigated,” they said.

The SROs also warned market participants to review their internal controls and procedures.