The main trigger sending AUD tumbling has been Australian treasury comments. As DJN reports, AUD Treasury said "rates should be lowered if AUD too high", adding that any remote possibility of "intervention wouldn't work." The news, combined with rumours of CNY band widening, has seen AUD longs bailing themselves out of the market.
Today, in the inter-bank news, there has been growing talk on the recent rise in AUS government bond yields over the last month.As Peter Withley, analyst at IFR Markets, explains, "it looks at face value the bottom of the great bull run for bonds is over. Whilst nobody is looking for a rout, safe haven flows (and thus AUD support) might have had its run."