BOJ Rate Hike Delayed to 2027 Renders $100B Yen Intervention Pointless

Woofun AI reports that Goldman Sachs predicts the BOJ’s next rate hike is delayed until January 2027, maintaining a wide interest rate gap. Consequently, Wall Street argues that recent $100 billion joint US-Japan interventions are merely buying time and cannot sustainably reverse the yen’s decline without fundamental policy shifts.

The scale of recent market operations has reached unprecedented levels, yet the immediate aftermath reveals a stark disconnect between official action and market sustainability. On August 3, Japan’s Finance Ministry confirmed it had acted together with the Treasury to purchase nearly $100 billion worth of yen within two days—a record amount—and warned it would act again if necessary. This marked the first time the US and Japan had coordinated to intervene in the currency market since the Fukushima nuclear disaster in 2011. Following this news, the yen initially strengthened significantly, creating a brief illusion of stability.

However, the sustainability of this rally is in doubt, as the yen has already dropped by over 200 points from its post-intervention high, following a path very similar to that seen after the intervention on April 30 this year—rapid gains followed by quick reversal by the market. The core issue lies not with the intervention itself but with the BOJ. As long as the interest rate gap between the US and Japan remains wide, there is no solid reason for the yen to rally.

Goldman Sachs economists’ current baseline forecast is that the BOJ will raise rates again in January 2027, meaning the short-term interest rate gap of over 200 basis points between the two countries will persist for a long time. "It’s highly likely the yen will continue to weaken," they say—what the intervention buys is merely time. In other words, as long as the BOJ does not raise rates, such interventions are like using limited ammunition in a battle that cannot be won. On August 3, the DXY closed almost flat that day, while the yen ended at 156.99, rising by just 0.3%. This minimal movement underscores the market's skepticism regarding the durability of the recent support levels.

The sheer volume of capital deployed highlights the desperation of the current strategy. On Thursday, July 31, the single-day intervention volume was around 8.45 trillion yen (about $53 billion), setting a new record for the largest single-day intervention. Another round of intervention followed on Friday, involving about 5.3 trillion yen (around $33 billion). Together, these amounts totaled nearly $100 billion. After the intervention, the dollar/yen rate briefly dropped to 155.20 before rallying by over 200 points. Since September 2022, Japan’s Finance Ministry has intervened a total of over $255 billion, yet it has still failed to halt the long-term downward trend of the yen. The cumulative expenditure demonstrates that even massive liquidity injections are insufficient to counteract structural headwinds.

Despite this record-level intervention, Goldman Sachs’ research team (led by Mike Cahill) noted in its latest report that 'the market reaction was on the lower side compared to historical interventions, indicating that when the yen’s decline aligns with macroeconomic and fundamental market conditions, the marginal effect of interventions is diminishing—even though they still have some impact.' The diminishing returns suggest that the market has adapted to the presence of official buyers, treating them as a temporary floor rather than a reversal signal. This erosion of effectiveness is a critical variable in assessing future policy options.

Woofun AI data shows that analysts believe the root cause of the yen’s weakness lies in the interest rate gap. The Fed funds rate in the US is much higher than the BOJ’s policy rate. A gap of over 200 basis points means that those who short sell the yen and hold dollar assets can earn money every day. As long as this gap exists, there is incentive for carry trade activities to continue. Analysts point out that the increasingly frequent interventions by Japan’s Finance Ministry show that each intervention is becoming less effective. The market knows the Ministry’s resources are limited, is aware of Japan’s poor fiscal situation, and understands that the only way to truly reverse the yen’s decline—is through a significant rate hike, estimated by some to require an increase of 100 basis points—which is almost impossible in the foreseeable future.

The BOJ is the real variable here, constrained by domestic financial fragility. The BOJ’s current policy rate is 1%, the highest since 1995. Yet within hours after the intervention last week, the BOJ chose not to act and raise rates. Jesper Koll, an investment banker based in Tokyo, asked directly: Governor Kazuo Ueda confidently told us that he expects inflation in Japan to accelerate again to above 2% in the second half of the fiscal year, but then he chose not to take action. So why aren’t you raising rates? Is it because Japan’s financial system is too fragile, and faster rate hikes could trigger a banking crisis? The answer is almost obvious.

In Japan’s Treasury bond market, over half of the debt is held by the BOJ itself—because there are no other sufficient buyers. If interest rates rise rapidly, the prices of Treasury bonds will fall sharply, putting the entire fiscal structure at risk. Robin Brooks, a former Goldman Sachs foreign exchange strategist now working at the Brookings Institution, put it more bluntly: The yen is falling because Japan’s high public debt prevents the country from allowing yields to rise freely. He believes that the yen’s depreciation is essentially "a symptom of a hidden debt crisis." With bond yields suppressed, the yen becomes the most direct symptom of this hidden debt crisis.

Without rate hikes, everything is temporary. Goldman Sachs’ overall conclusion is that in the short term, the asymmetric risks for the dollar/yen pair suggest further declines. If the exchange rate breaks out above 158 again, authorities are likely to intervene once more. From a technical perspective, once 155 breaks down effectively, the next key support level is around 152. In the medium term, however, Goldman Sachs’ research team (led by Mike Cahill) believes that unless there are substantial changes in the policy mix or global growth prospects, encouraging capital repatriation will be the most powerful long-term tool to influence the yen’s exchange rate.

In other words, neither interventions nor gradual rate hikes are sufficient to sustainably strengthen the yen. Praneet Shah, Goldman Sachs’ global head of foreign exchange options trading, also warned that "in the medium term, a loose monetary and fiscal policy environment remains unfavorable for the yen, unless Japan truly raises its policy rates and sees substantial inflows of foreign direct investment.

Additionally, as intervention reserves are depleted, Japan will have fewer tools to defend its currency in the future, potentially leading to greater yen depreciation.'

Jesper Koll, an investment banker based in Tokyo who considers himself optimistic about the Japanese economy, also admitted that "it’s still highly likely the yen will weaken. The BOJ’s inaction stems from concerns about the regional banking system; moreover, the new fiscal policy will almost certainly lead to inflation, keeping risks skewed in favor of a weaker yen.' In other words, interventions can buy time, but not a lasting trend. If the BOJ does not raise rates, any intervention will eventually be absorbed by the market. The biggest tail risk: the collapse of carry trade.

Another deeper reason why yen interventions affect global markets is the massive scale of yen carry trade activities. Over the past five years, the strategy of borrowing low-interest yen to invest in high-yielding assets has generated returns that even surpassed the total return of the S&P 500. This strategy relies on a slow, predictable depreciation of the yen. If the yen appreciates rapidly, carry traders will be forced to close their positions, causing shocks to global risk assets.

Two years ago (in August 2024), carry trade activities were already partially liquidated in a "chaotic" manner, triggering severe volatility in global markets. This round of intervention has clearly disrupted the previously stable upward trend of carry trade. Jia Wen Tuea, a Goldman Sachs trader, noted that this is also one of the practical reasons behind the US’s participation in the intervention: "Japan is the largest foreign holder of US Treasury bonds. If Japan intervenes alone, it will need to sell Treasuries to obtain dollars to buy yen, pushing up US yields—which is also a problem for Washington.'

Goldman Sachs economists argue against the prevailing view, stating that inflation data is not sufficient to justify a rate hike by the BOJ in September. They maintain their baseline forecast—that the next rate hike will occur in January 2027. If this prediction proves correct, it means the interest rate gap between the US and Japan will remain unchanged for a long time. The logic behind carry trade will still hold, and the structural pressure for yen depreciation will not disappear. A more direct consequence is that the Treasury’s participation in these interventions could result in heavy losses—yen purchased with real money may depreciate significantly if the yen weakens again. Koll concluded that although he is optimistic about the Japanese economy, he still acknowledges that "it’s highly likely the yen will continue to weaken," with risks still skewed in favor of further yen depreciation.