Yen climbs to 155 per dollar as traders remain on intervention alert

Rally follows US-Japan coordination; finance minister suggests more action possible

On July 31, Japan purchased the yen "in coordination with the U.S. Department of the Treasury," Japanese Finance Minister Satsuki Katayama said in a statement on Aug. 3. (Nikkei montage/Source photos by Ken Suzuki, Shintaro Ino and Reuters) 

TOKYO -- The yen strengthened sharply to the lower 155 range against the dollar on Monday morning, as markets remain wary of further currency interventions by Japan and the U.S.