TL;DR
· The USD/JPY approached 164 in July, prompting escalated verbal intervention by Japan's Ministry of Finance.
· The market is reassessing the risks of interest rate hikes, pension fund rebalancing, and carry trade volatility.
· Underlying assets: USD/JPY, Japanese government bonds, Brent crude oil, U.S. equities, and the U.S. Dollar Index.
The USD/JPY approached 164 in July, nearing a roughly 40-year low, after which Japan's Finance Minister, Katsunobu Kato, warned that the government would take "bold" action if necessary to counter disorderly movements.
For traders, the 163 to 165 range is not just an exchange rate zone—it’s a policy test zone. Will Japan directly buy yen? Will the Bank of Japan raise rates sooner than expected? Could carry trades borrowing yen to buy global assets be abruptly halted?
This market move is also easily misunderstood. A stronger stance from the Ministry of Finance does not mean intervention has already begun. Discussions about pension funds rebalancing do not mean the “national team” has already bought yen. What the market is pricing in is that Japan’s policy toolkit is expanding from verbal warnings to expectations of rate hikes and quasi-rebalancing buying.
The weakness of the Japanese yen has been transmitted to import inflation.
The problem with this yen depreciation is that it’s not occurring solely on the USD/JPY pair. The trade-weighted exchange rate is also at a low level, indicating that the yen is weak not just against the strong U.S. dollar, but against a basket of major trading partner currencies as well.
The trade-weighted exchange rate can be understood as a "comprehensive thermometer for the yen." If only the dollar is strong, the yen may not weaken against all other currencies in tandem. If the trade-weighted index also declines, imports, inflation, and household purchasing power will all come under pressure.
Oil prices have amplified the issue. Brent crude has recently been pushed up by conflicts in the Middle East, briefly nearing $100. Japan, being a major energy importer, faces higher costs for imported energy, food, and raw materials as rising oil prices combine with a weakening yen.
This is also why the Bank of Japan cannot fully treat exchange rates as merely an issue of the foreign exchange market. The weaker the yen, the higher the import costs, and the more persistent inflation becomes. Market expectations that rates may still be raised this year are not due to a sudden overheating of the Japanese economy, but rather because exchange rates and oil prices are altering inflation risks.
The Ministry of Finance first raises the cost of short selling.
Katayama Satsuki's firm stance first altered the risk-reward ratio of trades, rather than immediately changing the yen's fundamentals.
The Japanese Ministry of Finance can use verbal intervention to warn the market that continuing to short the yen may encounter policy shocks at any time. Especially when she mentioned the shared framework between the U.S. and Japan on taking action against disorderly movements, the signal is no longer just “we are watching,” but “we reserve the right to act.”
The threshold for direct foreign exchange intervention is not low. Buying yen and selling dollars consumes foreign exchange reserves. If oil prices, interest rate differentials, and dollar safe-haven demand remain unchanged, intervention is more likely to reduce short-term volatility than reverse the trend.
The latest monthly data available from Japan's Ministry of Finance is as of June 26, 2026. Between April 28 and May 27, Japan confirmed intervention of JPY 11.7349 trillion. Between May 28 and June 26, it was JPY 0. Whether Japan will intervene in July will be confirmed in upcoming monthly data.
For retail investors, the risk is not an immediate trend reversal upon the news, but rather having to pay a higher policy surprise premium on the same short yen position. Around 163 to 165, short sellers can still trade the carry, but their leverage tolerance is decreasing.
Rate hikes and GPIF are slower supports.
Compared to direct intervention, interest rate hikes by the Bank of Japan and rebalancing by GPIF are more like slow-moving variables, but their impact on pricing may be more lasting.
Japanese central bank officials have kept open the possibility of faster-than-expected rate hikes, and market surveys also indicate continued expectations for further rate increases this year. While not a formal commitment, this is sufficient to prompt traders to recalculate the U.S.-Japan interest rate differential.
The logic behind the Japanese yen carry trade is simple: borrow low-yielding yen and invest in higher-yielding dollar assets or risk assets. As long as Japanese interest rates remain low and the yen depreciates gradually, this trade is comfortable. However, if expectations of a Bank of Japan rate hike accelerate, or if the yen suddenly rallies, the cost of borrowing yen and exchange rate losses will rise simultaneously.
GPIF is Japan's Government Pension Investment Fund. The Japanese government has recently encouraged pension funds such as GPIF to increase domestic investments, a move that previously strengthened the yen and Japanese government bonds.
The GPIF has assets of approximately ¥293 to ¥294 trillion, with foreign assets totaling about $931 billion. If a portion of these funds is repatriated from overseas bonds or foreign assets to purchase Japanese government bonds or yen-denominated assets, it would create marginal support.
The boundaries here must be clearly defined. Rebalancing is more akin to an adjustment in asset allocation than traditional foreign exchange intervention. According to media reports citing Goldman Sachs’ estimates, the potential scale could range from tens of billions to around $80 billion. It may help cool off yen short positions, but it cannot be interpreted as actual policy-driven buying.
The auction results for Japan’s 40-year government bonds on July 22 also showed that demand remained solid despite higher long-term yields, exceeding some concerns. This has eased the narrative that "rate hikes will inevitably crash Japanese bonds" and strengthened another view: Japan’s policy mix is more likely to gradually increase the cost of shorting the yen rather than abruptly reversing the exchange rate direction.
Carry trades fear sudden price spikes.
What needs the most attention right now is not an immediate collapse of global carry trades, but a sudden spike in volatility.
Carry trades fear a rapid appreciation of the yen in a short period. If the exchange rate moves sharply in the opposite direction, positions funded by borrowing yen to purchase assets may be forced to liquidate. This triggers a chain reaction: buying back yen and selling risk assets, which then transmits foreign exchange volatility to U.S. equities, credit bonds, and high-yield assets.
However, current evidence is insufficient to support the claim that "full liquidation has begun." A more accurate statement is that yen short positions still exist, but the safety buffer has narrowed. Oil prices, policy statements, central bank meetings, and expectations of intervention are all reducing the margin for error on this trade.
163 to 165 are becoming policy test zones.
Key verification points will focus on: whether the Ministry of Finance's monthly data shows signs of actual intervention in July, whether the Bank of Japan's meeting signals a stronger rate hike, whether oil prices can remain elevated, and whether GPIF exhibits visible asset allocation moves.
If these variables simultaneously point to policy tightening, the 163 to 165 range will become the trigger band for repricing carry trades. Short yen positions will face higher volatility, more expensive hedging costs, and greater uncertainty regarding the timing of policy moves.
Conversely, if oil prices decline, central banks maintain a restrained stance, and no intervention data emerges, the yen’s weakness may persist. However, each approach toward a new low will increasingly trigger a policy risk premium compared to the past. For cross-asset investors, the yen is becoming part of the cost of leverage for global risk assets.