Japan's 30-Year JGB Auction Draws Weakest Demand in a Year as Bid-to-Cover Slides to 2.94 Ahead of BOJ Decision

Japan's auction of 30-year government bonds on June 10 drew the weakest demand since June 2025, with the bid-to-cover ratio falling to 2.94 from 3.49 at the previous sale and below the 12-month average of about 3.4. The average yield at the sale was recorded at 3.86%, after the 30-year yield had climbed to 3.94% on June 8, up 5 basis points on the session, in a high-yield environment for super-long Japanese debt.

Bloomberg reported that a decline in yields heading into the sale dented investor appetite, with concerns over inflation and fiscal policy weighing on sentiment, and that JGB futures extended declines after the result was released. The soft auction lands six days before the Bank of Japan's June 16 policy meeting, where markets price roughly an 80% probability of a rate increase as policymakers contend with persistent inflationary pressures linked to elevated energy costs; the BOJ is also expected to continue reducing its monthly bond purchases, withdrawing a structural source of demand from the long end of the curve.

Investors had flagged the sale as a key test of appetite for super-long duration as global long-end yields rise on fiscal concerns across major sovereign markets.