Yen surge tests Tokyo’s resolve

Japan’s yen rallied sharply against the dollar on Friday as traders braced for further official action from Tokyo after suspected currency intervention jolted global markets during a packed week of central bank decisions.

The dollar fell to around 155.60 yen at one point in London trading, before recovering part of the move to trade near 156.40. The rebound in the yen followed a dramatic reversal on Thursday, when the Japanese currency strengthened by about 3 per cent after the dollar briefly climbed above 160 yen, a level widely viewed in markets as politically sensitive for Tokyo.

Japan’s top currency official Atsushi Mimura said authorities remained concerned about speculative moves and were watching markets closely. Finance Minister Satsuki Katayama had already warned that Tokyo was ready to take decisive action if currency movements became disorderly. The comments reinforced market expectations that further intervention could follow, particularly during Japan’s Golden Week holiday period, when thinner trading conditions can magnify exchange-rate swings.

Bank of Japan money-market data suggested authorities may have spent about 5.48 trillion yen, or roughly $35 billion, to support the currency on Thursday. The scale would be close to the size of Japan’s July 2024 intervention, when authorities moved after the yen weakened to a 38-year low near 162 per dollar. Tokyo typically does not confirm intervention immediately, preferring to disclose monthly figures later, but unusually large projected fund flows at the central bank often provide an early signal of official activity.

The pressure on the yen has been building for months as the interest-rate gap between Japan and the United States remains wide. The Bank of Japan kept its policy rate at around 0.75 per cent this week, although three board members dissented and argued for a rise to 1 per cent. That split underlined growing concern inside the central bank that imported inflation, higher energy costs and yen weakness could feed into domestic prices.

The Federal Reserve also left rates unchanged, keeping its target range at 3.5 to 3.75 per cent. The gap between US and Japanese yields continues to encourage carry trades, in which investors borrow cheaply in yen and invest in higher-yielding dollar assets. Such positioning has made the yen vulnerable whenever markets believe Tokyo’s warnings lack force.

The intervention threat gained urgency after oil prices climbed on concerns over disruption linked to the Iran conflict and risks around the Strait of Hormuz. Japan, heavily dependent on imported energy, faces a double blow from higher crude prices and a weaker currency, which raises the local cost of fuel, food and raw materials. That dynamic complicates the Bank of Japan’s effort to normalise policy gradually without damaging a fragile recovery.

The broader central bank backdrop added to volatility. The European Central Bank kept its deposit rate at 2 per cent while signalling that inflation risks had intensified. The Bank of England held Bank Rate at 3.75 per cent in an 8-1 vote, with one policymaker favouring an increase. Across major economies, policymakers are balancing weaker growth signals against renewed price pressures from energy and supply disruptions.

Currency traders said Japan’s challenge is that intervention can slow a slide but rarely reverses a trend unless supported by monetary policy or a shift in global rates. A one-off operation may force investors to cut speculative positions, but renewed dollar strength can quickly restore pressure on the yen if US yields remain elevated and the Bank of Japan moves cautiously.

The timing of the suspected intervention was also significant. With European markets partly thinned by the May Day holiday and Japan heading into an extended holiday stretch, liquidity conditions were expected to remain fragile. Authorities have often chosen moments of thin trading to maximise the impact of currency operations, but such moves also increase the risk of sudden reversals when full market participation returns.

For households and companies in Japan, the exchange-rate battle has direct economic consequences. A weaker yen benefits exporters by raising the value of overseas earnings, but it also lifts import bills and squeezes consumers through higher costs. Large manufacturers have been able to absorb some of the pressure, while smaller businesses reliant on imported inputs face tighter margins.