Bessent’s $5-10 Billion Yen Intervention Lifts Currency From 40-Year Low, Sparks Market Tremors

The US Treasury joined Japan in a direct yen-buying intervention on Friday, marking the first time Washington has stepped in to buy the Japanese currency since 1998. The move was accidentally previewed when a Reuters photographer captured Treasury Secretary Scott Bessent’s notepad at a Camp David cabinet meeting, revealing a to-do list that included “Buy Japanese Yen (JPY) $5-10 bil.” The image, taken at 11:33 a.m. local time, showed Bessent’s name card positioned immediately above the notepad, leaving little doubt about the authorship of the plan.

The intervention itself was executed through direct purchases of the yen, according to Japan’s Finance Ministry, which confirmed the action in a statement on Monday. The US Treasury backed the move by selling euros, not dollars, to fund the purchases, a detail reported by CNBC that sparked debate among economists about the efficacy of the approach. The yen, which had been flirting with its weakest levels since 1986 at above 163 per dollar, rebounded sharply to 157.40 by the close of New York trading on Friday.

Before the intervention, the dollar was trading above 163 yen, touching 40-year highs that had sounded alarm bells in Tokyo as rising import costs squeezed businesses and consumers. After regulators were suspected of stepping in, the rate fell below 160. The official announcement on Monday sent the dollar to nearly 155.20 yen at one point, though it settled around 156.75 late Monday afternoon Tokyo time. By Tuesday, the yen held firm around 156.70, with traders remaining on edge about further action.

The scale of the move caught markets off guard. Macquarie Group strategist Gareth Berry told Bloomberg that “the price action alone looks like intervention,” noting the yen swung from a small decline to a 1.4% gain during morning trading in Tokyo on Monday. Some of the volatility was attributed to jittery traders and algorithmic programs reacting to the news, but the fundamental driver was the coordinated official action, which Fortune characterized as the tightest US-Japan coordination in decades.

One of the most debated aspects of the intervention is the funding mechanism. Instead of selling dollars to buy yen, the New York Federal Reserve reportedly sold euros to fund the purchase. Fortune reports that economists are questioning whether this approach undercuts the efficacy of US participation, citing concerns that using a third currency introduces a “twist” that could backfire. The intervention lifted the yen to 157 per dollar, but critics argue it does nothing to fix the underlying interest-rate differential between the US and Japan that has driven the yen’s years-long decline.

The move marks the first time the US and Japan have jointly bought the yen since 1998, during the Asian financial crisis. The degree of coordination now appears to be the tightest in decades, raising the stakes for traders who have been betting against the yen. The yen’s slide has stoked inflation in Japan and rippled through global markets, making the intervention a high-stakes gambit for both governments.

US Treasury Secretary Scott Bessent confirmed the action in a statement, saying “Friday’s coordinated foreign exchange actions countered disorderly yen movements.” Japan’s Finance Ministry went further, declaring it “will not hesitate to conduct further coordinated interventions in the future” and remains in close communication with the US Treasury. Bessent echoed that readiness, signaling to markets that the two nations are prepared to repeat the operation if needed.

President Trump addressed the intervention in characteristically unorthodox fashion, framing it as a favor between friends. According to Fortune, Trump remarked that “Japan’s been very good to us, with the exception, of course, of Pearl Harbor,” an awkward historical reference that dressed up the rare joint market move as a personal gesture. The statement confirmed both sides had intervened, sending the dollar lower against the yen on Monday.

The coordinated intervention has reset the risk calculus for currency traders betting against the yen. Bloomberg notes that US and Japanese officials warned investors they are determined to keep defending the currency, putting short sellers on notice. The yen’s sharp swings, including a 1.4% intraday gain followed by a partial retracement, created a volatile environment that punishes one-directional bets.

The yen’s years-long slide, driven by the wide gap between US and Japanese interest rates, has been a one-way trade for much of the past two years. The intervention doesn't close that gap, but it signals that the US is now willing to use its own balance sheet to support the yen, a dynamic that changes the risk-reward for carry traders. The degree of coordination, which Fortune described as the tightest in decades, means traders now face the possibility of repeated official action.

Despite the dramatic rebound, economists caution that the underlying drivers of yen weakness remain intact. The interest-rate differential between the US and Japan is the fundamental force behind the yen’s decline, and an intervention that sells euros rather than dollars does not address that gap. Fortune quotes economists who say the unusual funding method undercuts the efficacy of US participation, calling it a “twist” that may limit the long-term impact.

The yen has been sliding for years, and a single intervention, even a coordinated one, is unlikely to reverse that trend permanently. The question now is whether the US and Japan are willing to sustain the effort, and whether the Federal Reserve and Bank of Japan will adjust monetary policy in ways that support the yen. The intervention buys time but does not solve the structural problem.

The immediate focus is on whether the US and Japan will conduct further interventions, as both Bessent and Japan’s Finance Ministry have signaled they are ready. The yen’s reaction to the Monday announcement, including a partial retracement from 155.20 to 156.75, shows that markets are testing the resolve of officials. Traders will be watching for signs of additional purchases, and the $5-10 billion figure from Bessent’s notepad suggests the US is prepared to commit significant resources.

Beyond the immediate intervention, the yen’s trajectory will depend on the Federal Reserve’s interest-rate path and the Bank of Japan’s willingness to normalize its own policy. The coordinated action has bought Japan time, but the underlying economic forces that pushed the yen to 40-year lows have not changed. The intervention is a tactical victory, but the strategic battle over the yen is far from over.