But it is clear that the magnitudes are huge. Aggregate daily trades of all currencies on the Australian market are probably at least as large as the $ billion exchanged each day through the domestic payments system. Some banks seem to have a poor understanding of exactly when receipts become final in those countries which do not settle foreign exchange transactions in real time.
There is some evidence of a “no news is good news” policy in respect of assuming settlements have occurred. Finally, for even the major currency pairs traded out of Australia, the period of foreign exchange settlement risk (leaving aside weekends and holidays) frequently lasts for more than 24 hours. In some instances, it extends into a third day.