日圓持續走軟的主要驅動力來自「利差交易」（carry trade）。由於美國政府債券殖利率居高不下，而日本利率依然偏低，投資人藉由借入廉價的日圓，轉而投資高收益的美國資產或科技股。此外，日本散戶投資者也開始恢復針對高收益貨幣的日圓空頭部位。
雖然目前利差交易無序平倉的風險較低，但若真的發生，將對全球金融資產造成廣泛衝擊。歸根究底，只要美國高殖利率持續且日本央行堅持謹慎升息，在這些根本因素改變之前，日圓仍將是具有吸引力的做空標的，政策干預的長期效果將十分有限。
Despite a historic joint US-Japanese intervention two weeks ago that temporarily pulled the dollar down to ¥156, the exchange rate has rebounded to ¥159. Markets remain defiant, with investors consistently and heavily selling the yen every day since the intervention, signaling a strong willingness to fight against policymakers' efforts to support the currency.
The persistent weakness of the yen is largely driven by the carry trade phenomenon. With US government bond yields remaining exceptionally high and Japanese interest rates staying low, investors borrow cheap yen to fund higher-yielding investments in US assets and tech stocks. Additionally, Japanese retail traders are rebuilding short yen positions against high-yielding currencies.
While the risk of a disorderly unwind of these carry trades is currently considered low, such an event could broadly impact global financial assets. Ultimately, as long as high US yields persist and the Bank of Japan maintains a cautious approach to rate hikes, the yen will remain an attractive sell. Interventions are unlikely to have a lasting impact until these underlying fundamental factors shift.