Japan's 10-year bond yield tops 3% for first time since 1996, sounding alarm for Takaichi's fiscal expansion

Japan's benchmark 10-year government bond yield briefly touched 3.000 percent during trading Tuesday, rising 0.06 percentage point from Monday — the first time the yield has crossed the 3 percent threshold since September 1996, a 30-year high. When Prime Minister Takaichi Sanae took office last October, the long-term rate stood at just 1.6 percent, meaning it has nearly doubled in less than a year.

The surge reflects a confluence of forces: expectations of further Bank of Japan rate hikes, concerns about tightening in the United States, and growing market wariness toward the Takaichi government's aggressive fiscal expansion. As the interest burden on government bonds mounts rapidly, the room for the administration to pursue its signature tax cuts and spending increases is narrowing.

The rate spike has both external and domestic drivers. On the external side, hawkish remarks by Federal Reserve Chair Kevin Warsh on Friday (local time) reinforced expectations of a US rate hike in September, pushing up long-term US yields and triggering a weaker yen and stronger dollar in currency markets.

The yen briefly fell to the 160-per-dollar level on Monday. Markets grew increasingly concerned that a weaker yen would intensify inflationary pressure and prompt the Bank of Japan to raise rates sooner than expected, triggering a sell-off in bonds.

Global factors — including inflationary pressure stemming from the Middle East — have also played a role, though analysts note that Japan's pace of yield increases has been steeper than that of the United States or major European economies.

On top of those external pressures, the Takaichi cabinet's "proactive fiscal" policy stance is acting as a domestic upward force on yields, the Nikkei reported.

The Japanese government finalized a growth strategy in July to channel more than 370 trillion yen ($2.32 trillion) in combined public and private investment across 17 strategic industries by 2040. In August, it decided to temporarily cut the consumption tax rate on food to 1 percent for two years starting in April 2027. Budget requests for fiscal year 2027, submitted by the end of last month, swelled to around 143 trillion yen under general account terms after a new growth-investment category with effectively no spending cap was introduced, and a further increase in defense spending is expected to be decided by year-end.

The central problem is that no concrete funding plan has been presented for the consumption tax cut or the defense buildup.

Market unease had already flared once in July, when it emerged that the phrase "fiscal consolidation" had been dropped from an early draft of the government's basic economic and fiscal policy guidelines — known as the "Honebuto Policy." The revelation triggered a sharp spike in yields in what markets dubbed the "Honebuto Shock," a bout of financial market turmoil in which government bond yields surged and the yen weakened amid concerns over the Takaichi cabinet's expansionary fiscal stance.

Takaichi moved to contain the fallout at the time, saying she did not believe her policies were the cause of rising yields and that exchange rates and interest rates are determined by many factors. But market anxiety did not subside, and long-term yields have climbed to the brink of 3 percent.

The issue is also bound up with the fundamental direction of fiscal management. Rather than maintaining the previous government's goal of running an annual primary balance surplus across central and local governments combined, Takaichi has said she will anchor fiscal policy around steadily reducing the ratio of government debt to GDP.

Reducing reliance on supplementary budgets and keeping new government bond issuance below the prior year's level are extensions of that approach. Even on Aug. 5, when the consumption tax cut was finalized, the prime minister emphasized that her administration had "managed fiscal policy with sufficient regard for fiscal sustainability and maintaining market confidence."

Yet as rising yields inflate the interest burden on government bonds, the fiscal space available for tax cuts and spending increases shrinks accordingly. With Takaichi's fiscal-discipline message failing to fully resonate with markets, bond investors are in effect sending the government a warning signal about its expansionary stance.

Markets are interpreting the breach of 3 percent as simultaneously a sign of Japan's escape from deflation and a return to financial normalization — and a warning from the bond market against further fiscal expansion. With additional Bank of Japan rate hikes also on the horizon, how convincingly the Takaichi government can present a credible funding plan for its consumption tax cut and defense buildup before year-end is seen as the key factor that will determine the direction of yields going forward.