The yen carry trade: the fuse is now in Japanese bonds

The yield on the Japanese 10-year government bond reached 2.88% on 9 July 2026, its highest level since 1996, at the end of nine straight sessions of gains. A bond move in Tokyo may seem distant. Yet it touches one of the most discreet cogs of global finance: the yen carry, the cheap funding that irrigates risk assets across the planet. The danger has changed address.

Until now, Japanese risk read off the exchange rate: a USD/JPY glued to 162, a threat of intervention from Tokyo, the fear that a forced repurchase of yen would trigger a disorderly exit from the carry. That grid stays valid, but a second front has opened, and it comes from the bond market. Japanese long rates are rising, fast, and this rise attacks the carry through a channel other than the exchange rate. Here is why it matters.

The yen carry, how it works

The yen carry trade rests on a simple idea. You borrow in the world’s cheapest currency, the yen, whose rates stayed close to zero for twenty years, and place the proceeds in better-remunerated assets: US Treasuries, equities, credit, emerging currencies, sometimes crypto. The gain is the yield gap, the carry. As long as the yen stays weak and markets are calm, the position banks a steady income with comfortable leverage.

Its size is hard to quantify because it mixes bank, speculative and corporate positions. Estimates range from a few hundred billion dollars for the speculative core alone to an order of magnitude of $4 trillion for the broader web, depending on the perimeter used. This imprecision is itself information: no one knows the exact size of the short yen position, which makes any unwind impossible to calibrate in advance. The carry works like an implicit sale of volatility: it earns bit by bit, then can cost dearly all at once. Two conditions support it, a yen that does not rebound sharply and a Japanese yield that stays negligible. The second has just cracked.

The new trigger comes from the bond market

On 9 July 2026, the 10-year JGB yield reached 2.880%, its highest since September 1996, its ninth consecutive session of gains, the longest run in nineteen years. The move is sharper still at the long end of the curve: the 30-year rose to 4.030% and the 20-year to 3.85%, an unprecedented peak since 1996 too. For a market used to floor-glued rates, this is a regime change.

The immediate cause is fiscal. The government unveiled a long-term economic strategy aiming to mobilise more than 370 trillion yen, about $2.29 trillion, of public and private investment by fiscal year 2040 to strengthen strategic industries. The market translated this programme into a single question: who will finance this extra debt, and at what price? The answer is being written in the auctions, where investors now demand a higher yield to absorb Japanese paper. The local press even coined a word for the episode, the “Honebuto shock”, after the government’s fiscal framework.

Three channels of contagion

Why do rising Japanese rates threaten assets on the other side of the world? Through three distinct channels, which can play together.

The first is the compression of the carry. The carry lives off the gap between a near-zero yen funding cost and a high foreign yield. If the Japanese yield climbs, the opportunity cost of the strategy rises: keeping your savings in Japan becomes less penalising, borrowing in yen more so. The relative advantage of the trade narrows from below, even before the yen moves.

The second is repatriation. Japan is a major creditor to the rest of the world and, per US Treasury TIC data, the largest foreign holder of Treasuries. Japanese life insurers, pension funds and banks hold mountains of foreign bonds. The day the 10-year JGB offers a decent yield in local currency, with no exchange risk, part of these savings can flow back to Tokyo. This repatriation pushes selling of foreign assets, including Treasuries, which tightens their yields and squeezes global liquidity. It is the same interconnected world described in our guide to the Treasury market: exchange rate, sovereign debt and market funding are not separate subjects.

The third is the central bank’s trap. The BoJ remains the largest holder of JGBs, with a share only just back below 50% of the market in early 2026, against a peak of 53% in 2023. It is now shrinking its balance sheet through quantitative tightening, preferring, per Wolf Street, this route to aggressive rate hikes to support the yen. But this withdrawal has a mechanical effect: the less the BoJ buys, the fewer captive buyers there are, and the more long rates rise. The central bank is thus caught between two dangers, letting rates run at the risk of a bond accident, or buying back at the risk of reviving yen weakness. Each option feeds a facet of the carry risk.

August 2024, the quantified precedent

A brutal unwind is no textbook hypothesis. The market saw it on 5 August 2024, when a first BoJ tightening and poor US data triggered a flash rebound in the yen and a chain liquidation. The Bank for International Settlements made it the subject of a dedicated bulletin.

The lesson of this episode is twofold. First, the transmission is mechanical: to meet margin calls on FX losses, investors sell what they can, that is, the most liquid assets, including those with nothing to do with the yen. Second, and this is the essential, the 2024 tremor settled only an estimated 10% or so of a position core on the order of $500 billion. The rest stayed in place. The carry did not disappear in 2024; it was reloaded, and today it lives under the threat of a new trigger.

The possible paths

Three outcomes emerge. These are analyst scenarios, not forecasts, and the order in which I present them does not prejudge their probability.

The first path is an orderly retreat. The BoJ calibrates its quantitative tightening, long rates rise in digestible steps, and the carry shrinks gradually as the yield gap closes. Investors have time to unwind without trampling each other. It is the scenario the central bank seeks, and its prudent management so far, a yen defended by the balance sheet rather than by abrupt hikes, points that way.

The second is the trap the BoJ would like to avoid. If long rates run away, the temptation will be strong to slow the withdrawal, or even to buy back JGBs to calm the curve, a de facto return toward yield curve control. But each such move weakens the yen, revives the appeal of the carry and pushes the problem back while enlarging it. The central bank would buy time against an even heavier short position.

The third is the accident. An auction that goes badly, a fiscal slip or a confidence shock, and long rates tighten too fast. Repatriation kicks in, the yen firms all at once, volatility explodes and the unwind becomes forced, as in August 2024, but on a broader position base. This scenario is not the most probable, it is the most costly, and it is the one to guard against.

Why the worst is not written

It would be dishonest to present only the alarmist thesis. Several factors argue for a landing without drama. Japanese debt is held more than 90% by residents, which makes a buyers’ strike far less likely than in a country dependent on foreign capital: an Italian- or British-style failed auction remains improbable in Japan. The BoJ retains, with yield curve control, an instrument able to cap long rates overnight if it deems it necessary. And the 2024 episode itself showed a capacity for rapid rebound: once the shock passed, markets and the yen had stabilised within a few weeks, without a lasting systemic crisis.

Above all, a rise in Japanese rates can reflect good news, the finally successful exit from three decades of deflation, rather than a distress signal. A Japan normalising its rates because its economy holds up is a healthier Japan, even if the transition roughs up a speculative trade. The nuance has its flip side: at 2.88%, the Japanese yield stays far below the 4% and more of Treasuries, so the carry keeps a margin and its disappearance is nothing imminent. The risk is not that the carry collapses tomorrow. It is that a poorly measured stock of positions unwinds one day in disorder, and that the fuse, this time, was lit in Tokyo, on the bond market, where few people were looking.

Sources

1. Business Recorder / Reuters, 10-year JGB yield at 2.880% on 9 July 2026, highest since September 1996, ninth session of gains (longest run in 19 years), 30-year at 4.030%, 20-year at 3.85%: https://www.brecorder.com/news/40429220/japan-benchmark-bond-yield-extends-rise-after-hitting-30-year-high
2. Yahoo Finance / Reuters, benchmark JGB at a 30-year high amid fiscal concerns: https://finance.yahoo.com/economy/policy/articles/japan-benchmark-bond-yield-hits-004445377.html
3. StoneX, Japanese investment plan of more than 370 trillion yen ($2.29 trillion) by fiscal 2040, pressure on the curve and carry trades: https://www.stonex.com/en-us/insights/japan-yield-curve-pressure-threatens-global-carry-trades/
4. Trading Economics, 10-year JGB yield series: https://tradingeconomics.com/japan/government-bond-yield
5. Bank of Japan, monetary policy decision of 16 June 2026, policy rate raised to 1.00%: https://www.boj.or.jp/en/mopo/mpmdeci/index.htm/
6. Nippon.com, BoJ share of the JGB stock (peak of 53.34% in March 2023): https://www.nippon.com/en/japan-data/h01720/
7. Nikkei Asia, BoJ share of JGB holdings back below 50% in early 2026: https://asia.nikkei.com/business/markets/bonds/bank-of-japan-s-share-of-jgb-holdings-dips-below-50
8. Wolf Street, the BoJ favours quantitative tightening over rate hikes to support the yen, 3 July 2026: https://wolfstreet.com/2026/07/03/qt-instead-of-rate-hikes-to-put-a-floor-under-plunging-yen-bank-of-japan-sheds-15-6-of-its-massive-assets/
9. Bank for International Settlements, Bulletin no 90, “The market turbulence and carry trade unwind of August 2024” (Nikkei -12.4%, VIX beyond 65, unwind of about 10% of positions estimated at $500 billion): https://www.bis.org/publ/bisbull90.pdf
10. U.S. Treasury, TIC data, major foreign holders of Treasuries: https://ticdata.treasury.gov/resource-center/data-chart-center/tic/Documents/slt_table5.html