Japan intervened in their foreign exchange rates after the yen hit a post WWII high against the dollar.

The dollar spiked after the intervention as much as 4 percent past 79 yen from around 75.65 yen. The dollar touched a record low of 75.31 yen earlier on Monday.

Finance Minister Jun Azumi said Tokyo stepped into the market for the second time in less than three months on its own at 10:25 a.m. local time (0125 GMT) and would continue to intervene until it was satisfied with the results.

The Yen is considered safe haven and there have been other recent interventions:

Monday’s maneuver was the fourth time in just over a year that Japan has intervened to stem the yen’s rise.

The BBC reports the Yen dropped 5% to the dollar after the move. One must wonder why is such speculation going on with the Yen, which is considered save haven. It seems in spite of the big Greek debt haircut and U.S. Q3 GDP of 2.5%., markets are leery and believe little has be resolved.

It seems speculators are ganging up on the yen in spite of Japan's quantitative easing:

Last week, the Bank of Japan eased its monetary policy again by expanding the asset purchase by JPY 5 trillion to JPY 20 trillion. The central bank governor Masaaki Shirakawa pointed to the yen strength as the reason behind the move.

During the monetary policy meeting on Thursday, the bank decided to maintain the interest rate near-zero. With the central bank action, the total size of the asset purchase program moved up to JPY 55 trillion, including the credit facility, which was unchanged at JPY 35 trillion.

The response of speculators was to double down:

According to the Commitment of Traders report, currency speculators doubled their net long position in the yen to 54,279 contracts in the week ended October 25, the highest since the beginning of August, the latest U.S. CFTC data shows.