On Friday, July 31st, the USD/JPY pair became the core of volatility in the foreign exchange market. The recent price action first peaked around 163.98, then quickly dropped to 157.96, with a maximum range of nearly 600 pips, currently hovering around 160.20. The daily price briefly broke below the lower Bollinger Band, and the MACD histogram turned sharply negative, indicating that this was not a typical technical pullback, but rather a liquidity shock caused by a combination of policy funds, month-end portfolio adjustments, and concentrated liquidation of highly leveraged positions. Market information suggests that Japan may have implemented large-scale yen buying operations, and the South Korean market also saw dollar selling, further amplifying the synchronized volatility of Asian currencies. Based on calculations of changes in the Bank of Japan's accounts, the scale of this operation may reach 8.2 trillion to 8.45 trillion yen, equivalent to approximately 53 billion to 59 billion US dollars, potentially approaching the highest single-day record. As the official daily operation details have not yet been released, the exact amount still awaits confirmation from subsequent fiscal data.

Why has massive intervention failed to change the main trend of exchange rates?

Intervention can alter short-term order books, but it's difficult to change interest rate spreads alone. The Bank of Japan maintained its policy rate at 1% by a vote of 8 to 1. Hajime Takada advocated a 25 basis point hike to 1.25%, but this failed to gain support from other committee members. The Bank of Japan also lowered its core inflation forecast for fiscal year 2026 from 2.8% to 2.5%, signaling not an immediate acceleration of tightening, but rather continued observation of the transmission of previous rate hikes to the financing environment, wages, and demand. On the other hand, the Federal Reserve maintained its policy rate at 3.50% to 3.75%, with the short-term policy rate spread between the US and Japan remaining at approximately 2.5 percentage points. More importantly, the 2-year US Treasury yield rose to approximately 4.26%, and the 10-year yield approached 4.67%, indicating that market financing costs have not eased significantly due to the short-term decline in the US dollar. As long as interest rate spreads and carry trade profits persist, the yen appreciation caused by intervention could easily trigger short covering, but it may not be able to sustainably attract medium- to long-term funds. Therefore, this volatility is more akin to position liquidation than a trend reversal. The price quickly rebounded from 157.96 to above 160, reflecting that some funds viewed the intervention low as a liquidity window to re-establish carry trade positions. The larger the scale of intervention but the shorter its duration, the more it indicates that the authorities are combating structural interest rate spreads rather than ordinary speculative volatility.

Why did Kazuo Ueda's statement fail to set a clear anchor for interest rate hikes?

Following the meeting, Kazuo Ueda stated that the Bank of Japan could accelerate the pace of interest rate hikes if monetary conditions become excessively loose, emphasizing the need to avoid policy lagging behind inflation changes. He also pointed out that the transmission of exchange rate fluctuations to prices is strengthening, and acting too late could force the central bank to take more abrupt adjustments in the future. However, from a pricing perspective, such statements still fall under the category of conditional guidance. Japanese government bond yields are at cyclical highs, and the stock market has already declined significantly from historical highs, making it difficult to simply define monetary conditions as excessively loose. Meanwhile, only one member supported an immediate rate hike, indicating that the committee has not yet reached a consensus on accelerating tightening. The market's real focus is not on whether the Bank of Japan retains the option of raising interest rates, but rather on whether the interval between the next rate hike will shorten. Current pricing partially points to September or October, but the probability distribution remains relatively dispersed. If subsequent wages, service prices, and inflation expectations do not rise in tandem, a significant disconnect will still exist between intervention and interest rate policy.

The core variables in the next phase will shift from intervention to inflation and liquidity.

The USD/JPY pair faces three key variables. First, US inflation data. Energy prices and the Middle East conflict could still influence inflation through transportation and production costs, and the next consumer price data will directly impact market expectations for the Fed's September policy. If expectations of a rate hike intensify, the USD/JPY interest rate differential could widen again. Second, whether Japan will intervene continuously. Single-day operations can reduce leverage, but continuous operations are needed to alter the market's perception of policy response. The Bank of Japan anticipates an unusual outflow of approximately 8.2 trillion yen from the money market, providing a crucial basis for intervention projections. However, before the official data release, the market will likely continue to discount the scale and sustainability of the intervention. Third, the liquidity structure around 160. The chart shows the Bollinger Bands' middle band at approximately 162.34 and the lower band at approximately 160.24, with the price returning to near the lower band after extreme volatility. At this point, technical indicators reflect a surge in volatility rather than a signal of stabilization. If the price re-enters the 160-162.3 range, the market may shift from policy shocks to interest rate repricing; a rapid drop below 158 would indicate that deleveraging is not yet complete.