The main reason for the yen's strength is the data we got overnight -- it suggests deflation is coming to an end.

There was an upgrade in the economic assessment by the BOJ and comments from governor Fukui. From that point of view an end to the zero interest rate policy is coming closer.

The Fed is close to the end of its rate hike cycle while the ECB is just beginning, which removes support for the dollar.

After we failed to break the year's lows against the euro, people decided to take some money off the table. Hedge funds are among those selling the dollar, and they're causing this sharp move upward.

A coalition of this kind would hurt the reform process considerably, and that's worrying the market. I'd expect to see further euro weakness ahead of the election.

Today's decision means the end of zero interest rate policy is coming closer. Less liquidity is available for yen carry trades and that should be positive for the yen.