Japan warns yen speculators it stands ready to intervene again

Japan's top currency officials kept up pressure on traders on May 1, warning that speculative yen moves remain a concern and that Tokyo is ready to intervene again if needed.

Finance Minister Satsuki Katayama had already said on April 30 that the timing for taking "decisive action" in the foreign-exchange market was nearing. Reuters reported that she also told reporters to keep their smartphones with them during the holidays, a remark widely read as a sign that intervention could come at any time.

Top currency diplomat Atsushi Mimura added on May 1 that speculative moves were still present in the market and declined to comment on future action. His comments extended a week of increasingly direct warnings from Tokyo as the yen came under pressure.

Reuters reported earlier that Japan had intervened to support the yen, which surged sharply after the move. The report said it was Japan's first official currency intervention in nearly two years.

The warnings matter because they came as Golden Week began, a holiday period when Japanese markets are closed for several days and liquidity can be thin. That can make the currency more vulnerable to sharp moves and makes official signaling more consequential.

For now, Japan has left traders with a clear message: speculative selling of the yen could trigger another round of intervention, even if officials are not confirming every market action outright.