An aberration in the reported exchange rate for AUD/USD in the early hours led some sharp price movements on Australian bitcoin exchanges. Google data reported that the AUD had sharply appreciated against the USD.
Arbitrageurs (likely automated trading bots) attempted to capitalize on the perceived AUD appreciation by executing market sales of bitcoin on local exchanges. The order book for Bitaroo was depleted multiple times. Some trades were executed at rates as low as 27k AUD/BTC, which is a discount of about 10% to the current rate.
The exchange rate aberration in reports of the AUD/USD pair have been corrected now and the reported exchange rate is now at about 1.57 AUD/BTC.