On September 15th, BoJ intervened on the forex. USDJPY jumped 3,3%, to the level from the end of August. Can this action stop the strenghtening of Japanese yen?
An interesting study on Japanese forex interventions in 1990s was prepared by Takatoshi Ito from Institute of Economic Research, Hitotsubashi University.
The amount of money used by the Bank of Japan for the intervention should be disclosed on November 8th on the page dedicated to Foreign Exchange Intervention Operations maintained by the Ministry of Finance in Japan: http://www.mof.go.jp/english/e1c021.htm
The amount of the intervention is estimated at 1 trillion JPY (11,7 billion USD).
The first test of the effectiveness of the intervention may come on Tuesday, September 21st, when FOMC announces its interest rate decision and possibly further plans for quantitative easing.