Bank of America characterizes foreign exchange intervention as an intermittent but potent policy instrument among major economies. Recent episodes involving the Japanese yen and the Swiss franc highlight how official actions can reverberate beyond currency markets, touching reserve holdings and the trading of U.S. Treasuries.
According to the research, authorities generally deploy intervention only in episodes of extreme volatility, notable currency misalignment or broader financial stress. When they do act, direct market operations are frequently paired with public guidance or official comments designed to shape investor expectations.
In the United States, responsibility for exchange-rate policy rests with the Treasury, while the Federal Reserve Bank of New York conducts operations on the government's behalf. Washington's longstanding preference for market-determined exchange rates means intervention remains an uncommon tool in normal conditions. Since 2000, the U.S. has taken part in only two significant coordinated currency operations: one to support the euro and another following Japan's 2011 earthquake and the Fukushima nuclear disaster to stabilize the yen.
Bank of America points to Japan and Switzerland as among the more active G10 central banks in recent years. Tokyo has intervened repeatedly since 2022 to support the yen, and the research notes likely operations this year after sharp moves in USD/JPY raised concerns about imported inflation and financial stability. Swiss authorities have also made intervention part of their policy toolkit, at times selling francs to curb excessive appreciation and at other times buying francs to help contain inflationary pressures.
The analysis argues that interventions coordinated with wider economic policy measures tend to exert the strongest influence. Non-transactional tools - such as official warnings and so-called "rate checks" - can also move markets by adjusting expectations before any trades occur.
Beyond immediate currency effects, intervention can change central bank balance sheets, alter domestic liquidity conditions and shift reserve asset compositions. Large adjustments to reserve portfolios can in turn affect U.S. Treasury yields and swap spreads, the research notes, illustrating the broader market footprint of what might at first appear to be isolated FX operations.
Even with these potential impacts, Bank of America underscores a limitation: intervention by itself seldom redirects a currency's long-term trajectory. Sustained currency movements, the research says, are more often the product of evolving economic fundamentals, shifts in monetary policy expectations and changes in investor sentiment.