The yen strengthened suddenly and significantly against the dollar Thursday night in a jump that suggests intervention by the Japanese government.

Around 10:30 p.m. Thursday, the currency went from ?162.80 to the ?157 mark to the dollar in a matter of about an hour.

As of Friday noon, the yen was trading at around ?160.70.

No official confirmation of a possible intervention was made, as Finance Minister Satsuki Katayama on Friday declined to comment on whether the government had made a move.

¡°Given such a sharp currency move over a short period without any major news drivers, it is natural to assume that financial authorities intervened in the market,¡± said Takahide Kiuchi, executive economist at Nomura Research Institute, in a report released on Friday.

U.S. authorities reportedly conducted a rate check, suggesting possible joint action with Japan. A rate check, where a central bank asks financial institutions for exchange rates, is widely seen as a precursor to an intervention.

U.S. Treasury Secretary Scott Bessent also reportedly told Fox Business on Thursday that the yen is undervalued.

Katayama has repeatedly issued verbal warnings in the past several weeks that the government will take action if needed.

The move came after the yen broke through ?163 to the dollar last week ¡ª a four-decade low for the currency ¡ª partly due to escalating Middle East tensions that prompted safe-haven dollar buying.

The timing also coincides with the conclusion of the U.S. Federal Reserve¡¯s Federal Open Market Committee meeting on Wednesday that decided to maintain its policy rate. It is conceivable that Japan waited to see the subsequent reaction of the Fed¡¯s policy decision, as a rate hike was not completely ruled out by investors.

If the Fed had raised rates or sent a clear hawkish signal, the yen would likely have faced further downward pressure.

Although the Japanese government appeared to have finally stepped in, analysts expect the effects of the intervention to be short-lived.

A $73 billion intervention that began in late April, after the yen breached ?160 to the dollar, briefly pushed the currency back to around ?155. But those gains vanished within a month.