US regulators are poised to introduce measures that would ensure anonymity for traders in the $700 trillion market for swaps, said people familiar with the discussions, a flip-flop that would hand a victory to hedge funds and speedy trading firms while dealing a blow to banks.

The planned action from the Commodity Futures Trading Commission would encourage trading among any and all market participants, mirroring futures markets that the agency also oversees, and would raise the chance of traders dealing directly with one another, potentially bypassing banks that have historically been major providers for these complex transactions, the people said.