The Commodity Futures Trading Commission has subpoenaed ISDA, ICAP and as many as 15 banks regarding possible manipulation of a swaps benchmark, sources say. The investigation reportedly is focused on ICAP brokers who allegedly failed to update published market prices after trades occurred. "ISDA received a subpoena related to ISDAFIX and has provided information in response to the CFTC's request," according to the association. "We are cooperating fully." ISDA and ICAP, which manages ISDAFIX, say the calculation process includes strict controls and oversight.