Joint US-Japan Intervention Fails to Halt JPY Slide Amid Rate Hike Speculation

Japan and the US have jointly intervened in currency markets to stabilize the Japanese yen, which has fallen to 40-year lows. The intervention is seen as a way for Tokyo to buy time until it can implement a Bank of Japan (BOJ) rate hike, penciled in for as early as September.

The BOJ warned on Friday that underlying inflation could exceed its target, marking the clearest signal yet that a hike is coming. However, experts remain skeptical about the effectiveness of the intervention, with some arguing that it won't address the JPY's long-term decline unless the BOJ hikes rates and US interest rates move lower.

The joint intervention saw Japan buying yen and selling dollars in New York hours on Thursday, while the US side was executed quietly. The exact amount spent by the US wasn't disclosed, but Treasury Secretary Scott Bessent accidentally flashed his notepad during a televised meeting, revealing that he had USD 5-10 bn listed as 'To Do: Buy Japanese Yen (JPY)'.

The intervention has sparked debate about its effectiveness. While Brent Donnelly of Spectra Markets points out that most joint interventions coincided with an actual turn in the USD/JPY trend, Dominic Bunning of Nomura remains skeptical, calling it 'tacit support more so than explicit coordinated intervention'.

The BOJ's decision to hike rates is seen as crucial for stabilizing the yen. If Tokyo is forced to sell down its Treasury holdings to fund a unilateral JPY rescue, it could trigger a selloff in US debt and cause an unwelcome spike in US yields.