
On Tuesday, Japan's government bond market experienced an unusual “long-end uncontrollable” sell-off: ultra-long-term yields reached record highs, with trading moving rapidly from calm to liquidity tension. The market attributed this volatility to rising concerns about fiscal discipline combined with weakening auction demand, leading to a self-reinforcing selling pressure.
Sell-off Accelerates: Ultra-Long-Term Rates Hit New Highs
During the session, the yields on Japan's 30-year and 40-year government bonds surged by more than 25 basis points, marking significant volatility rarely seen in recent years. Meanwhile, the 10-year yield rose by 16 basis points over two days, while the 30-year yield jumped about 38 basis points, showing clear signs of passive “risk premium compensation” at the long end.
Market participants described an obvious acceleration of selling in the afternoon, with some investors being forced to stop-loss: hedge funds unwinding losing positions and life insurance institutions also appeared to be selling, further draining the capacity to absorb long-duration bonds.
Rising Policy Uncertainty: Tax Cuts and Increased Spending Ignite Fiscal Concerns
Multiple institutions and traders are focusing on the fiscal path: with elections approaching and calls for tax cuts increasing, the market is starting to re-evaluate Japan's financing pressure and fiscal sustainability. Reuters reported that campaign promises surrounding tax cuts and fiscal stimulus have fueled concerns about fiscal discipline among investors, pushing long-end yields higher.
Reports also mentioned that related policy ideas might create a substantial fiscal gap, combined with Japan’s already high government debt burden, making it the most sensitive issue in the market as to “who will absorb the additional long-duration supply.”
20-Year Auction Cools Down: Weak Demand Signal Amplifies the Chain Reaction
Earlier in the day, Japan's 20-year government bond auction saw a lukewarm response, acting as one of the catalysts for worsening sentiment. Market perspectives suggest that a single weak auction might not be enough to trigger such a steep decline, but in an environment where fiscal concerns have accumulated, poor bidding acts more like an “igniter,” driving the sell-off in a loop.
What's Next to Watch: Absorptive Capacity, Central Bank Expectations, and Volatility Management
In the short term, the market may observe three main cues:
1) Whether new “stable buyers” for ultra-long duration appear (particularly questioning whether traditional absorbers like life insurers return);
2) Whether a clearer fiscal stance on financing and expenditure constraints emerges;
3) Whether expectations of the Bank of Japan's policy shift even further forward—Reuters noted that the market is also digesting the possibility of tighter monetary policy, which could increase volatility in long-end rates.





