STORY: Japan’s yen jumped in a sharp move on Friday (May 1).It comes after the country’s top foreign exchange diplomat warned Tokyo was ready to step back into markets.Atsushi Mimura’s words came only hours after official buying lifted the currency.The price move and comments led to speculation among currency traders of another round of intervention by Japan.The U.S. dollar dropped in the London morning, falling by as much as 0.66% to a session low.It wasn’t immediately clear what was behind Friday’s move, but analysts said after Thursday the market was on edge.Tokyo’s ramped-up rhetoric comes as the yen stays under pressure from wide U.S.-Japan interest rate gaps.And it’s also ahead of a holiday stretch officials fear could bring speculative attacks.Japanese markets will be closed on Monday through Wednesday for Golden Week.Analyst have said this could cause wild swings in the yen due to thin liquidity,.Japanese Finance Minister Satsuki Katayama’s warned on Thursday “decisive action” was approaching.She also told reporters to keep their smartphones on hand throughout the holidays.This was seen as a signal of Tokyo’s readiness to intervene and put off speculators from exploiting thin liquidity to push the yen lower.Two sources said Japan stepped into the market to support the yen just hours after Katayama spoke.That would mark its first official currency intervention in nearly two years.The reported move sent the Japanese currency as much as 3% higher.Mimura declined to comment on whether Japan intervened in the currency market on Thursday.He further said Japan is in “extremely close contact” with the U.S..And both countries agree action may be needed depending on market developments.The yen surged to 155.5 per dollar after Thursday’s intervention.But it later trimmed some gains and stood at 156.99, still above the 160 mark seen as the Japanese authorities’ marker for intervention.