Regulators have revised new rules on margining for uncleared over-the-counter derivatives in an attempt to reduce the risk of a collateral crunch. The new regime requires initial margin to be exchanged between swap counterparties, giving rise to warnings that it could lock down more than $10 trillion in liquid assets. But regulators estimate the revised proposals will consume around €0.7 trillion, in large part because the first €50 million of exposure between two counterparties would not need