Japan's yen buying coincided with 2% daily gains, and the April one lasted five weeks

Japan's Ministry of Finance bought yen on six days in 2026, and the first days of buying in April and in late July each coincided with a rise of more than 2% in the yen against the dollar, according to the Federal Reserve's H.10 series and the ministry's intervention data. By October 30 the rate was back at 157.47 yen per dollar, within 0.3% of the low after the second round.

Two purchases, two one-day moves of more than 2%

The Fed's historical series for the Japanese yen, published in the H.10 release of November 2, gives daily rates. On April 29 the rate was 160.23 yen per dollar. On April 30, the day the ministry bought ¥6,278.7 billion, it was 156.66, a 2.2% fall in the dollar-yen rate, which means a stronger yen (computed).

The second round began on July 30. The rate was 163.86 on July 29 and 159.47 on July 30, a fall of 2.7% (computed), on the day the ministry bought ¥7,975.6 billion, according to its quarterly report. After the third day of buying, August 3 (¥1,871.4 billion), the rate was 156.96, 4.2% below July 29 (computed).

The ministry publishes its figures only after each quarter ends, so the Fed series is the record of what the currency did on those days.

The April gain was gone by June 5

After April 30 the rate drifted back up. It was 158.08 on May 14, which means the yen had given back about 40% of the one-day move by then (computed from 160.23, 156.66 and 158.08). On June 5 it was 160.26, above the 160.23 of April 29. The ministry's data file shows two more days of buying in the period, May 4 (¥780.2 billion) and May 6 (¥4,675.9 billion), and the rate on May 6 was 156.44. Even so, five weeks after the first day of buying, the one-day gain had been fully reversed.

Between early June and late July the dollar kept rising against the yen, reaching 163.86 on July 29, the highest rate in the series this year. The lowest was 152.64 on February 12.

After August 3 the yen settled near 157 without new buying

The second round faded more slowly. On August 12 the rate was 159.23, so the yen had given back about 33% of the drop between July 29 and August 3 (computed). From August 4 to October 30 the range was wide, from 153.50 on September 9 to 160.03 on September 1, yet the ministry reported no purchases after August 3, and its monthly report for September 29 through October 28 shows ¥0.

On October 30 the rate was 157.47. That is 3.9% below the July 29 level and 1.7% below the April 29 level, but only 0.3% above the August 3 low (all computed). Put differently, the yen has held most of the second round's gain through nearly three months, which the first round did not.

The gap between the two central banks has not closed

The ministry's operations act on the exchange rate directly, while interest rates are set by the central banks. The Federal Reserve kept its target range for the federal funds rate at 3-3/4 to 4 percent on October 28, and two members, Lisa D. Cook and Beth M. Hammack, preferred a quarter-point increase. Two days later the Bank of Japan said it would encourage the overnight call rate to remain at around 1.25 percent, by an 8-1 vote. The lower end of the US range is 2.5 percentage points above the Japanese rate (computed). FinanceInTime covered the Bank of Japan's decision and the dollar's rise in October when they happened.

What the data do not show

The ministry does not say why it bought on any date, and the Fed series does not say why the rate moved afterward. The data do not show whether the September 9 low of 153.50, which came with no reported buying, reflected expectations about policy or something else, and they do not separate the effect of the purchases from other news on the same days. Both rounds began on days with large purchases and a rate move of more than 2%, but that is a sequence, not a measurement of cause.

What the pattern asks of the next test of 160

We think the record so far reads less like a defense of a level than like a way of buying time. Our reading is that the April purchases bought about five weeks, and the July and August purchases have so far bought about three months, which suggests that the second round benefited from something besides the ministry's money, though the data cannot say what.

The opportunity for Japan is that a smaller gap between US and Japanese interest rates, whether from the Bank of Japan raising its rate or the Fed easing, would take pressure off the yen without more spending. The threat is the reverse: if the Fed's two dissenters turn out to speak for a majority, the gap widens and the ministry's third round would face a rate near 160 with a larger cost. We expect the rate to be tested again if the Fed keeps its range and the Bank of Japan holds at 1.25 percent, and we would watch the ministry's next monthly report and the dollar-yen rate near the 160 area. Our view would change if the rate falls toward 153 without any purchases. This is a conditional forecast, not a price target.

The view in this final section is FinanceInTime's editorial opinion, for information only. It is not investment, tax, legal or other advice, and it does not take your circumstances into account. Forecasts are uncertain and past results do not guarantee future ones.