David Fuller's view Subscribers may recall that I am personally short the yen against the US dollar (USD/JPY) (monthly, weekly & daily). I established this trade too soon because on listening to complaints about yen strength from some of Japan's industrialists and also the government, and on seeing one day of unilateral intervention by the BoJ - with hindsight, probably under duress - I backed what I felt were fundamentals favouring yen weakness, rather than the price chart action as it subsequently deteriorated.

That was not smart, particularly from someone who stresses the importance of market trends. I also underestimated the determination of BoJ Governor Masaaki Shirakawa to assert his independence. He is far happier with a strong currency than most other central bankers (see also yesterday's interview with the BoJ Governor).

Nevertheless, Mr Shirakawa participated in multilateral intervention to weaken the yen on March 18th. Clearly, the earthquake, tsunami and Fukushima crises make the need for yen weakness rather than strength compelling. I also think that the repatriation argument for further yen appreciation is overstated.

Meanwhile, the charts will show us. Recent action, in addition to USD/JPY above looks interesting: EUR/JPY, GDP/JPY, AUD/JPY, CHF/JPY and SGD/JPY, to mention a few. No doubt there will be some choppy reactions but overall, I think short yen could be the best forex trade for a number of months as former yen bulls to become born-again yen bears.