Tokyo Burns $34.5 Billion: Japan Intervenes in the Yen for the First Time Since 2024

On Thursday morning, the yen slid past 160 per dollar, and the yield on Japanese government bonds hit the highest level in nearly three decades. Hours later, the Bank of Japan and the Ministry of Finance moved in, buying yen and selling dollars. The currency snapped back from 160 to 155.5 in hours.

According to a Bloomberg analysis of central bank accounts, Tokyo likely spent around 5.4 trillion yen ($34.5 billion) on the day. Nikkei's read of BOJ money-market data put the figure closer to 5 trillion yen ($32 billion). It is Japan's first foreign exchange intervention since July 2024.

Why the yen broke

Three pressures lined up at once.

The Fed-BOJ rate gap is wide and not closing. The Federal Reserve held rates and warned about persistent inflation, citing high oil prices on the back of the Iran war. The market priced out near-term Fed cuts.

The BOJ talked tough on Tuesday, then did nothing. At its monetary policy meeting, the central bank signaled that hikes were nearing, but kept the policy rate unchanged. The market read it as bluff.

Speculators piled in. CFTC data showed short-yen positioning at the largest level since July 2024, around $7.5 billion notional, ahead of Japan's Golden Week holidays.

Katayama's phone warning

Finance Minister Satsuki Katayama issued a verbal warning about the yen's weakness on Thursday, telling reporters that "decisive action" was nearing. After the intervention took effect, she added an unusual instruction. "Please keep your smartphones with you at all times, whether you're going out or resting," she said, ahead of the long holiday week.

Top FX diplomat Atsushi Mimura backed the message on Friday. "I won't comment on what we'll do ahead. But I will tell you that Japan's Golden Week holidays have just started," he said. The yen jumped again on his comments, briefly touching 155.60.

The structural problem

FX intervention treats the symptom, not the cause. The cause is the rate gap. Until the BOJ actually moves, the carry trade rebuilds.

"The yen will remain under downward pressure on inflation concerns from high oil prices, slow BOJ rate hikes and the hawkish tone of other central banks," said Rinto Maruyama, FX and rates strategist at SMBC Nikko Securities, after the intervention.

Japan last burned through real reserves to defend the yen in July 2024, when the currency hit a 38-year low at 161.96. The Golden Week stretch through next Wednesday is the next pressure test.

Sources: Bloomberg, Nikkei, Reuters, Business Times SG