The reform of the Dutch pension system may result in a selloff in long-maturity bonds and interest-rate swaps, the European Central Bank (ECB) warned Wednesday.The ECB wrote in its Financial Stability Review that demand for these securities will drop as Dutch pension funds shift from a defined benefit to a defined contribution model to better suit the needs of an aging population.While the changes have been well-flagged and are playing out over several years, the Dutch pension system has a large footprint in European rates markets. It accounts for about 65% of euro area pension funds’ sovereign bond holdings, according to the ECB.Shifts in demand for bonds are in particular focus given the pivot among European governments toward bigger defence and infrastructure spending, against a backdrop of higher debt sales globally. Long-maturity yields rose to multi-year peaks around the world earlier in 2025 amid bouts of volatility.With central banks — including the ECB — shrinking the bond portfolios accumulated during the years of quantitative easing, there’s now greater impetus on private buyers to absorb the supply hitting the market.“There is lower demand for longer-dated debt from some institutional investors, notably Dutch pension funds,” the ECB wrote in Wednesday’s report. “As a result, investors may require higher yields to absorb new issuance or a compressed maturity profile.”So far, a repricing in the euro swaps curve has been orderly. Still, the ECB is not the only market observer to warn of potential price swings as the transition advances.The Dutch central bank has said it’s working with the sector “to ensure a smooth and careful transition,” while Bank of America Corp has said it will keep trading desks fully staffed over the end-of-year period to be ready for potential volatility.The transition will be split across the next two years. The early part of 2026 is seen as a key test with about 35% of the Dutch pension sector’s assets due to switch over, according to BNP Paribas SA analysis. Total assets under management are about €1.9tn ($2.2tn), according to Dutch central bank data.The funds will also have less need for long-dated interest-rate hedges under the new system. Bets on a steeper curve — where long-end yields rise more than the shorter ones — was a popular bet for much of this year as investors positioned to profit from the Dutch shift.“This year’s surge in long-dated euro-area swap rates looks set to continue into 2026 after the European Central Bank added a note of caution about the impact of the Dutch pension-fund reform. ...The reform will see funds transitioning to asset allocations that have a shorter interest-rate hedge, leading to reduced demand for long-dated bonds and swaps and possibly increasing volatility in the market for long-term financial instruments,” says Ven Ram, Macro strategist at Bloomberg.The steepening move petered out in October amid doubts over the number of funds ready to change to the new system and their hedging requirements. But it has picked up again in recent weeks, a development that strategists have attributed to more Dutch pension funds getting the green light from regulators to make the switch.The gap between 10- and 30-year interest-rate swaps is around 32 basis points, the highest since 2021. It started the year around minus 20 basis points.