Belgium Raises €3.01 Billion in Bond Auction as 2036 Yield Reaches 4.299%

Belgium raised €3.009 billion in a government bond auction on Monday, with the yield on its June 2036 bond reaching 4.299% as borrowing costs at the sale moved higher than in the previous monthly auction. The Belgian Debt Agency accepted bids across three existing OLO lines maturing in 2031, 2034 and 2036.

According to the official auction results, Belgium sold €1.034 billion of the 3.10% OLO due August 2031 at a weighted average yield of 3.806%, €870 million of the 2.85% OLO due October 2034 at 4.117%, and €1.105 billion of the 3.40% OLO due June 2036 at 4.299%. The respective bid-to-cover ratios were 1.65, 1.61 and 1.72.

The €3.009 billion total was €9 million above the top of the €2.6 billion to €3.0 billion range the agency had announced before the auction. Settlement of the competitive bids is scheduled for September 30.

2036 yield climbs 49.4 basis points since August

The clearest change was in the 2036 line, OLO 106. Belgium last reopened that bond at its August 24 auction, when it accepted €1.266 billion at a weighted average yield of 3.805%. Monday’s 4.299% result was 0.494 percentage point higher, equivalent to 49.4 basis points.

Demand coverage on the same maturity was also lower than at the August sale. The bid-to-cover ratio fell to 1.72 from 1.93, while the amount accepted declined by €161 million. A bid-to-cover ratio above one means submitted bids exceeded the amount allotted, but the change from one auction to the next gives a more useful view of how much bidding stood behind the accepted amount.

The 2031 line showed a similar shift in yield. Its weighted average yield rose to 3.806% from 3.260% on August 24, an increase of 54.6 basis points. Belgium accepted €1.034 billion of the 2031 bond on Monday, compared with €825 million in August, while the bid-to-cover ratio moved down to 1.65 from 2.06. The 2034 line was not part of the August 24 auction, so there is no like-for-like monthly auction comparison for that maturity.

The 3.40% coupon on the 2036 bond should not be confused with the 4.299% auction yield. The coupon is fixed for the life of the bond, while the yield at a reopening reflects the price investors are willing to pay for that existing security. OLO 106 was first issued in January 2026 and matures on June 22, 2036.

Three reopened lines spread funding across the curve

Monday’s sale added supply at three different points of Belgium’s government bond curve rather than concentrating issuance in one maturity. Before the auction, the Debt Agency reported €9.657 billion outstanding in OLO 108 due 2031, €20.296 billion in OLO 100 due 2034 and €13.252 billion in OLO 106 due 2036.

Belgian OLOs are euro-denominated medium-, long- and very-long-term government securities. Regular auctions generally reopen existing lines, allowing new tranches to become fungible with bonds already outstanding under the same coupon and maturity. Only designated primary dealers participate directly in OLO auctions, submitting bids at different prices and quantities. The Debt Agency then establishes the minimum accepted price and allocates bonds under its auction procedure.

That structure means the government can build larger benchmark lines over time instead of issuing a completely new security for every financing operation. It also lets the agency choose which maturities to reopen according to funding strategy and market demand. The September sale followed the agency’s pre-announced calendar, while the specific lines and the target amount were disclosed closer to the auction date.

Bond sales remain central to Belgium’s 2026 funding plan

The auction sits within a year in which Belgium is relying heavily on OLO issuance to meet federal financing needs. The Debt Agency’s 2026 financing plan lists €59.55 billion of gross financing requirements for the year, including a €26.37 billion federal budget deficit, €28.00 billion of debt maturing in 2026 and €4.60 billion of planned pre-funding for bonds maturing in 2027 or later. The plan forecasts €51.60 billion of OLO issuance during 2026.

At the end of August, Belgium’s federal government debt stood at €578.169 billion, up €3.18 billion from July. Net debt, after deducting placements and securities held in portfolio, was €553.69 billion. The average maturity of federal debt was 10.17 years and the average interest rate on outstanding debt instruments was 2.24%.

Those portfolio-wide figures move more gradually than the yield on a single auction. A higher yield on a reopened 2036 line affects the cost of the new amount sold, but it does not reset the coupon or financing cost on Belgium’s existing stock of fixed-rate debt. The effect of higher market yields therefore feeds into the sovereign’s overall interest burden over time as new debt is issued and older debt is refinanced.

The September competitive auction settles on September 30. Belgium’s indicative 2026 OLO calendar lists the next regular auction for October 26, although the Debt Agency notes that the calendar can be changed. An Optional Reverse Inquiry facility is also scheduled for October 2, giving primary dealers a separate mechanism to request auctions of bonds that are difficult to source in the market.