The yen has tumbled back to its starting point after a brief rebound, despite a record-breaking intervention effort of nearly $74 billion within a month, now hovering perilously close to the 160 threshold.
Data released by Japan's Ministry of Finance on May 29 confirmed that authorities spent approximately 11.73 trillion yen (around $73.6 billion) buying yen to support the currency between April 28 and May 27, marking the largest intervention on record.
However, the effect of this "epic" intervention lasted less than a month. By the midday session in Tokyo on June 1, USD/JPY was trading at 159.49, dangerously close to the 160.72 level seen just before the intervention on April 30.
Traders' focus is now shifting from the Ministry of Finance's "ammunition" to the Bank of Japan, with the June 16 interest rate decision becoming the critical crossroads that will determine the yen's short-term fate.
The "Brief Victory" of Record Intervention
The "Foreign Exchange Balance Operation Implementation Status" data published by Japan's Ministry of Finance on May 29 revealed that during the intervention window from April 28 to May 27, authorities deployed a total of 11.73 trillion yen (approximately $73.6 billion) for yen-buying, dollar-selling operations.
This scale not only significantly exceeded the market's previous estimate of about 10.08 trillion yen based on central bank flow data but also surpassed the 9.79 trillion yen spent in May 2024 and the 8 trillion yen from October 2011, making it the largest single-month intervention amount since Japan's data tracking began in 1991.
The actual timing of the intervention is also intriguing. Informed sources confirmed to media that the first salvo was fired on April 30, the day the yen briefly broke through 160.72. Subsequently, the market widely speculated that Japan conducted multiple rounds of "stealth intervention" during the Golden Week holiday in May.
Rinto Maruyama, Senior FX and Rates Strategist at SMBC Nikko Securities, noted that the fact the actual intervention size exceeded market expectations "raises the possibility that authorities conducted covert interventions within the 158.50 to 159.50 yen range."
Yet, the effectiveness of this "epic" intervention might best be described as "fleeting." On the day of the intervention, April 30, USD/JPY plunged sharply from 160.72 to around 155.50, a daily swing exceeding 5 yen. However, in less than a month, the yen had nearly erased all its gains.
On May 29, the final day of the intervention window, USD/JPY was at 159.27. By the Asian morning session on June 1, the pair had climbed further to 159.49, just a step away from the 160 level. For the entire month of May, the yen depreciated by approximately 1.74% against the dollar.
Bart Wakabayashi, Tokyo Branch Manager at State Street Bank, offered a pointed assessment: "It did have an impact at the time. But I don't think they succeeded in changing the market's psychology."
Why Did the Intervention Fail? Interest Rate Differentials, Energy, and the BOJ's "Tardiness"
Why has intervention struggled to reverse the yen's downtrend? Fundamentally, the forces driving the yen's depreciation are not from "speculative raids" but from the persistent resonance of three deep-seated structural factors.
First, the vast US-Japan interest rate gap is difficult to bridge. Since the outbreak of the Middle East conflict, expectations for Federal Reserve rates have undergone a dramatic reversal—from widespread bets on rate cuts at the start of the year to traders now pricing in the possibility of a hike before the end of 2026.
In stark contrast, while the Bank of Japan is slowly exiting negative interest rates, its current policy rate is only 0.75%, with a potential hike to 1.00% pending confirmation at the June meeting.
Analysts at StoneX point out that even if the BOJ raises rates as expected, the yield spread between the US and Japan remains at historically extreme levels, constituting the core macro factor pressuring the yen.
Second, the energy shock exposes Japan's structural vulnerability. As one of the world's largest energy importers, Japan is highly dependent on Middle Eastern crude oil. Following the disruption of shipping through the Strait of Hormuz due to US-Iran tensions, Japan's crude oil imports in April plummeted by nearly 66% year-on-year to 850,000 barrels per day, the lowest level since 1967.
Surging oil prices combined with a weak yen create "double-barreled imported inflation" pressure—the corporate goods price index rose 4.9% year-on-year, while import prices surged by as much as 17.5%. This "cost-push inflation" fails to stimulate consumption and instead erodes corporate profits and household purchasing power.
Third, the Bank of Japan's "slow pace" is testing market patience. With inflation having exceeded the 2% target for many consecutive months, the BOJ's pace of rate hikes is widely perceived by the market as "overly cautious."
Former BOJ Policy Board member Makoto Sakurai issued a blunt warning in an interview on May 29: "If they don't hike rates in June, policy will fall behind the curve. This meeting is extremely important." He added that missing this opportunity could lead to the next rate hike being postponed indefinitely due to the high uncertainty surrounding the Middle East situation.
In contrast, US Treasury Secretary Besant, during her visit to Tokyo this month, clearly signaled support for a BOJ rate hike. Sakurai noted, "Considering the diplomatic relationship between Japan and the US, the BOJ will likely have no choice but to accept a rate hike." This assessment has tangibly impacted market expectations—overnight index swaps show traders' bets on a BOJ rate hike on June 16 have risen to about 78%.
The BOJ's Dilemma: Rate Hikes, Balance Sheet Reduction, and "Three Fronts"
The Bank of Japan's policy meeting on June 16 is becoming one of the most complex policy battlegrounds in recent years. Governor Kazuo Ueda faces at least three intertwined fronts.
Front One: To Hike or Not to Hike. Inflation data sends mixed signals. Tokyo's core CPI in May rose only 1.3% year-on-year, below expectations and the smallest increase in four years. However, Sakurai points out that this slowdown was temporarily influenced by "technical factors" (education and water supply subsidies), and core inflation is likely to reaccelerate to above 3% this autumn or later.
Amid this complex picture of "short-term weakness, medium-term rebound," the BOJ faces a difficult trade-off between "waiting for clearer signals" and "preventing itself from falling behind the curve."
Front Two: The Bond Purchase Program. The recent surge in Japanese Government Bond yields has heightened market tension. The 10-year JGB yield has climbed to 2.8%, a high not seen since 1996; the 30-year yield briefly touched a historical peak of 4.2%. Rapidly rising yields directly increase the government's debt financing costs—a significant concern for a country with government debt around 250% of GDP.
Sources indicate that the BOJ is internally discussing whether to pause further reductions in its JGB purchase scale for the 2027 fiscal year to prevent yields from spiraling out of control. Sakurai commented that "stopping the slowdown in bond purchases is also acceptable."
Simultaneously, the BOJ faces pressure from the Japanese government's plans for significant fiscal expansion. Prime Minister Hayashi Sanae is preparing a supplementary budget of around 3 trillion yen to mitigate the impact of rising international energy prices on Japan's economy and livelihoods amid the ongoing Middle East conflict.
Front Three: The Exchange Rate Floor. The 160 level is widely seen by the market as the Ministry of Finance's "line in the sand." Marito Ueda, Managing Director at SBI FX Trade, stated plainly: "USD/JPY is very likely to break 160, at which point the Ministry of Finance will have to intervene again."
But intervention "ammunition" is not infinite—while the nearly $74 billion spent is still only a portion of Japan's approximately $1.17 trillion in foreign exchange reserves, large-scale sales of US Treasuries could provoke dissatisfaction from the US.
More importantly, as Masahiko Loo, Senior Fixed Income Strategist at State Street, summarized: "Intervention only buys time; it cannot change the situation—the real shift must come from the Bank of Japan."
Market Positioning: Shorts Pile On and "False Breakout" Risks
During this policy decision vacuum, speculative capital is repositioning. Data from the Commodity Futures Trading Commission for the week ending May 26 shows that leveraged funds and asset managers have increased their net short yen positions to the highest level since July 2024.
This means the market is voting with its positions—betting that the BOJ's actions in June will be insufficient to reverse the yen's weak trend.
Technically, the 160 level has become the key battleground. Analysts note that USD/JPY's plunge from 160.72 to 155.50 on April 30 provided the market with a clear "policy reaction function"—authorities will intervene decisively near 160.
However, this information itself could be used against the market: some traders are considering positioning in advance, betting the next round of intervention might come when USD/JPY rises to around 162.
StoneX analyst David Scutt noted in a quarterly outlook report that if USD/JPY decisively breaks through the 2024 high of 161.95, "there is little immediate resistance in sight, with the next technical reference point pointing directly to the September 1978 low of 177.05."
If the BOJ opts to hike rates by 25 basis points to 1.00% while signaling a "pause in balance sheet reduction," this would be interpreted by the market as a "hawkish-dovish" combination—acknowledging inflationary pressures require a policy response but unwilling to exacerbate bond market turmoil by further tightening liquidity.
This combination might offer limited support to the yen, as the US-Japan yield gap remains significant, and the market could interpret the "pause in reduction" as the BOJ's concern over the economic outlook.
If the BOJ unexpectedly stands pat, the market reaction could be more severe. Sakurai warns that not hiking could lead to further yen weakness, "and that would anger the US."
Given that Besant has explicitly advocated for Japan to address yen weakness through rate hikes rather than intervention, if the BOJ takes no action in June, it could trigger a new wave of large-scale selling, pushing USD/JPY toward 165 or even higher.
Meanwhile, geopolitical uncertainty remains the largest exogenous variable. As of June 1, US-Iran ceasefire talks have yet to achieve a breakthrough. Iran's Supreme Leader Khamenei recently issued a strong statement accusing the US and Israel of trying to "force the country to submit."
Brent crude extended gains during the Asian session on Monday, and the direction of energy prices will continue to influence the yen exchange rate through both trade terms and inflation expectations.
Comments