On December 19, 2025, the Bank of Japan raised its policy rate to 0.75%, marking a 30-year high in an effort to curb inflation and halt yen depreciation. However, the market's reaction was unexpected and counterproductive to these intentions.

Following Governor Ueda Kazuo's press conference, the yen rapidly depreciated to the 157 level against the dollar, its weakest position in approximately four weeks. The governor's cautious, data-dependent stance on the pace of future rate hikes led markets to interpret that the BOJ's room for additional tightening was limited.

Finance Minister Katayama Vows "Resolute Action"

In response to this sharp yen decline, Finance Minister Katayama Satsuki has expressed strong concern. After the G7 finance ministers and central bank governors meeting on the evening of December 19, she stated that "there has been a one-sided and rapid movement in the past half-day and few hours, which we view with concern," emphasizing that "we will take appropriate action against excessive movements."

Furthermore, on December 22, in an exclusive interview with Bloomberg, Finance Minister Katayama made it clear that she is "prepared to take resolute action" against excessive and disorderly currency fluctuations. She made her willingness to intervene in the market explicit, characterizing post-BOJ press conference currency movements as "speculative rather than based on fundamentals," and explained that measures could be taken based on the September Japan-U.S. joint statement by finance ministers.

From Verbal to Actual Intervention? Market Vigilance Intensifies

Finance Minister Katayama's series of statements follows a pattern of escalating "verbal intervention." On November 12, she characterized the yen's weakness as "one-sided and rapid movement," stating for the first time that "negative aspects are becoming more prominent." On November 21, she remarked that forex intervention was "naturally considered" as an option, raising the tone of caution.

With December's "resolute action" statement, market speculation has intensified that actual intervention may be imminent. Looking at past intervention records, in 2024, yen-buying interventions totaling approximately 15 trillion yen were implemented at the 160 yen level. The current 157 yen level is approaching that intervention threshold.

"Takaichi Trade" and Structural Factors Behind Yen Weakness

The persistent yen weakness has roots in the economic policies of Prime Minister Takaichi Sanae's administration. The Takaichi government, which took office in October, advocates aggressive fiscal expansion and continued monetary easing, creating what markets call the "Takaichi Trade": sustained yen-selling pressure.

The comprehensive economic package approved by the cabinet in November totaled 21.3 trillion yen, with a supplementary budget of 17.7 trillion yen, both substantial figures. Experts point out that this fiscal expansion stance is acting as a factor depreciating the yen's value.

Particularly noteworthy is that yen weakness continues despite a narrowing Japan-U.S. interest rate differential. Since the beginning of 2025, Japan's 10-year yield has risen by approximately 0.5%, while the U.S. 10-year yield has fallen by 0.5%. Yet the yen's depreciation trend persists, with market observers viewing this as "speculative movement that cannot be explained by fundamentals."

Japan-U.S. Joint Statement as Basis for Intervention

Finance Minister Katayama repeatedly references the Japan-U.S. joint statement issued by finance ministers in September 2025. This statement explicitly states that currency intervention is "equally appropriate in response to excessive volatility or disorderly depreciation or appreciation."

U.S. Treasury Secretary Bessent has also communicated via social media that the Japanese government's stance of giving the BOJ policy latitude is "key to stabilizing inflation expectations and avoiding excessive exchange rate fluctuations," indicating shared recognition between Japanese and U.S. monetary authorities regarding yen weakness concerns.

Market Response and Future Outlook

Following Finance Minister Katayama's statements, the yen temporarily strengthened from the 157.40 level to the 157.20 level. However, it subsequently returned to trading around the 157 level, suggesting that vigilance has not completely restrained market movements.

Among analysts, views include "155 yen is the first line of defense" and "actual intervention is likely as the rate approaches 160 yen." However, some cautious opinions suggest that "we haven't reached the eve of intervention, and yen strengthening will remain a temporary reaction."

Future focus will be on year-end and New Year currency fluctuations. During this period, market participation typically decreases, making speculative movements more likely to accelerate. Multiple factors will influence the yen's trajectory, including the scale of the fiscal 2026 budget and the timing of the BOJ's next rate hike.

Economic Impact and Public Life

Yen weakness presents a dual nature for the Japanese economy. Japan becomes an affordable destination for foreign tourists, and major export companies see profit increases. However, energy and raw material import costs rise, intensifying inflationary pressure on households.

Finance Minister Katayama's statement that "negative aspects are becoming more prominent" reflects awareness of these rising costs' adverse effects on citizens' lives. Concerns also exist about deteriorating profitability for domestic-oriented companies, placing the government in a position where yen weakness cannot be ignored.

While currency intervention is being actively discussed in Japan, what are the prevailing views on exchange rate policy and currency value in your country? What are your thoughts on government intervention in markets? We'd love to hear perspectives from your country's viewpoint.