In September, the bankruptcy of Lehman Brothers caused a total close to $400 billion to become payable to the buyers of CDS protection referenced against the insolvent bank. However the net amount that changed hands was around $7.2 billion. This difference is due to the process of 'netting'. Market participants co-operated so that CDS sellers were allowed to deduct from their payouts the inbound funds due to them from their hedging positions. Dealers generally attempt to remain risk-neutral, so that their losses and gains after big events offset each other.