Despite Buffett's criticism on derivatives, in October 2008 Berkshire Hathaway revealed to regulators that it has entered into at least $4.85 billion in derivative transactions. Buffett stated in his 2008 letter to shareholders that Berkshire Hathaway has no counterparty risk in its derivative dealings because Berkshire require counterparties to make payments when contracts are initiated, so that Berkshire always holds the money. Berkshire Hathaway was a large owner of Moody's stock during the period that it was one of two primary rating agencies for subprime CDOs, a form of mortgage security derivative dependent on the use of credit default swaps.