Japan made no foray into forex market in Oct. after yen fall past 150

Japan stayed out of the currency market for one month to late October, Finance Ministry data showed Tuesday, despite the yen’s sharp appreciation fueling talk of intervention by the authorities after the psychological barrier of 150 to the U.S. dollar was breached.

The dollar tumbled about 3 yen in a short span of time on Oct. 3 in New York, an unusual move seen by some market players as the result of a yen-buying, dollar-selling operation by Japan. Japanese authorities neither confirmed nor denied they had stepped in.

The ministry data covered one month from Sept. 28 to Friday.

Finance Minist...