What Moves USD/JPY? Rate Gaps and Japan's Yen Buying

On 29 July 2026 one US dollar bought 163.86 Japanese yen. As at 9 October 2026, that was the weakest the yen had been against the dollar since December 1986.

USD/JPY is the price of one US dollar (USD) in Japanese yen (JPY). When USD/JPY goes up, the yen is weaker. You hand over more yen for the same dollar. This explainer shows what moves the pair: the gap between US and Japanese government bond yields, the Bank of Japan's dated decisions, then Japan's yen buying.

A currency pair is a price. USD/JPY is the number of Japanese yen you pay for one US dollar, so the dollar is the thing being priced.

That makes the direction awkward. When USD/JPY moves from 150 to 160, you hand over 10 more yen for the same dollar, so each yen buys less. A falling USD/JPY is a stronger yen.

Over the long run the pair has gone one way. A dollar cost 92.55 yen on 4 January 2010. It cost 158.34 on 9 October 2026, which is 71.1% more yen for the same dollar. Measured the other way round, the yen lost 41.5% of its dollar value.

The yen was at its strongest in this window on 28 October 2011, at 75.72 per dollar. It then weakened in two long steps, the first from late 2012, the second from early 2022.

The yen's weakest point came on 29 July 2026, at 163.86 per dollar. That is the highest the pair reached in this window.

Two dated markers matter. On 21 September 2016, at 100.62, the Bank of Japan began capping Japanese bond yields. On 19 March 2024, at 150.73, it stopped.

The 2-year government bond yield prices two years of a central bank's policy rate. Money flows towards the higher yield, so a wider US lead puts pressure on the yen.

The gap was 0.03 percentage points on 9 September 2011, when both central banks sat near zero. It peaked at 5.13 points on 17 October 2023, after the Federal Reserve raised rates while the Bank of Japan held.

On 9 October 2026 the US 2-year yield was 4.80%. The Japanese 2-year yield was 1.911%. The gap between them was 2.89 points.

Put the two charts side by side and the shapes line up. Measured at month ends from January 2010 to October 2026, the correlation between the gap and USD/JPY was 0.80.

The link is strong, yet it does not explain everything. The gap averaged 2.67 points in 2018, when USD/JPY averaged 110.40. In 2026 to 9 October the gap averaged 2.55 points, while USD/JPY averaged 158.51.

Other forces fill that difference. Japan's trade position swung from surplus to deficit over the same period, which adds steady yen selling.

Under the framework it set out on 21 September 2016, the Bank of Japan charged minus 0.1% on part of the reserves banks hold with it. Reserves are the money banks park at the central bank. It also introduced yield curve control, buying Japanese Government Bonds to hold the 10-year yield around zero.

That combination pinned Japanese yields down while US yields climbed from 2022. On 19 March 2024 the Bank of Japan ended both policies, guiding its overnight rate to around 0% to 0.1%. It stopped buying exchange-traded funds on the same day.

Five rate rises followed. The policy rate went to around 0.25% on 31 July 2024, then 0.5% on 24 January 2025. After that came 0.75% on 19 December 2025, 1.0% on 16 June 2026, then 1.25% on 18 September 2026.

The Federal Reserve moved in the other direction for part of that period. It cut its target range from 5.25% to 5.50% in steps, reaching 3.50% to 3.75% at the end of 2025. It then raised the range to 3.75% to 4.00%, where it stood on 13 October 2026, which kept the gap open.

Japan's Ministry of Finance decides on intervention, which means buying yen in the foreign exchange market to slow a fall. The Bank of Japan carries it out as its agent.

The 2022 round came in two bursts. On 22 September 2022 the Ministry bought 2.84 trillion yen. On 21 October it bought 5.62 trillion, then 0.73 trillion on 24 October. USD/JPY fell 7.0% from 20 October to 15 November 2022.

The 2024 round was larger. The Ministry bought 5.92 trillion yen on 29 April 2024 and 3.87 trillion on 1 May, then 3.17 trillion on 11 July plus 2.37 trillion on 12 July. USD/JPY fell 7.0% from 10 July to 31 July 2024, matching the 2022 fall to one decimal place.

The 2026 rounds were larger again. The Ministry bought 6.28 trillion yen on 30 April 2026, then 0.78 trillion on 4 May and 4.68 trillion on 6 May. Those three days came to 11.73 trillion yen.

As at 13 October 2026 the 30 April 2026 operation is the biggest single day of yen buying in the Ministry's records, which start in April 1991.

A second round followed that summer. The Ministry bought 15.4 trillion yen between 30 July and 26 August 2026. As at 13 October 2026 that is the largest month of yen buying in those records.

Intervention slows a move without changing what caused it. The pair fell from 160.23 on 29 April 2026 to 156.44 on 6 May. By 29 July it had reached 163.86.

The yield gap is the first driver. Three more forces matter.

The second driver is risk sentiment. The yen has risen sharply during falls in share prices. The carry trade is one mechanism behind that: borrowing in yen at Japan's lower rate to buy assets that pay more abroad.

That borrowing adds to yen selling while it builds. Closing those positions does the reverse, fast. USD/JPY fell 8.3% between 20 February and 9 March 2020. It fell 4.3% between 31 July and 5 August 2024.

The third driver is Japan's trade position. Japan ran a goods trade surplus of $78.4 billion in 2010. It has run a deficit in 12 of the 15 years since, including $156.3 billion in 2022, then $18.5 billion in 2025. Importers paying for energy in dollars have to sell yen.

The fourth driver is flows into US Treasury securities. Japanese investors held $1,103.9 billion of them at the end of July 2026. Buying a dollar bond means selling yen. How much of the holding is hedged, which means locking in a future exchange rate, changes how much yen selling that involves.

Three free sources cover the whole picture. The Federal Reserve Bank of St Louis's FRED database carries the daily rate as series DEXJPUS, plus the US 2-year yield as DGS2. Japan's Ministry of Finance publishes Japanese Government Bond yields every business day, including the 2-year.

For intervention, the same Ministry posts its total at the end of each month, with a day-by-day breakdown once a quarter. The Bank of Japan publishes its meeting dates a year ahead, so you can see when the policy rate could change.

Read the pair as a rate story first. The US minus Japan 2-year yield gap explains most of the move since 2010. The Bank of Japan's dated policy changes explain the turning points. Japan's yen buying explains the sharp drops that follow a run.

A higher USD/JPY means a weaker yen. The pair is the number of yen needed to buy one US dollar, so you hand over more yen for the same dollar. The rate was 158.34 on 9 October 2026, against 92.55 on 4 January 2010, a period over which the yen lost 41.5% of its dollar value.

The main reason is the yield gap. US 2-year yields have sat well above Japanese ones since 2022, so money has flowed towards the dollar. On 9 October 2026 the US 2-year yield was 4.80%. The Japanese 2-year yield was 1.911%. Month-end readings of that gap and USD/JPY had a correlation of 0.80 from January 2010 to October 2026.

Yen intervention is Japan's Ministry of Finance buying yen in the foreign exchange market, with the Bank of Japan acting as its agent, to slow a disorderly fall. It bought 15.4 trillion yen between 30 July and 26 August 2026. Amounts are published monthly, with daily detail once a quarter.

The yen carry trade is borrowing in yen, where interest rates are lower, to buy assets that pay more elsewhere. It adds to yen selling while it builds. When it unwinds, the yen rises quickly: USD/JPY fell 4.3% in the three sessions from 31 July to 5 August 2024.

No. The Bank of Japan sets the policy rate, which feeds the yield gap that moves the yen. Currency intervention is the Ministry of Finance's decision. The Bank of Japan has raised its policy rate in five steps since March 2024, reaching around 1.25% on 18 September 2026.

This explainer is part of the YX Insights Academy. Each one takes a single idea and checks it against real data.

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