UK 30-year gilt yield tops 6% for first time since 1998

Start with the Budget arithmetic. Higher yields raise what the government expects to pay on its debt, and that eats into its fiscal headroom, the room left under its fiscal rules. Estimates suggest the sell-off threatens to cut Healey’s buffer from £26bn to about £13.8bn: yields at these levels have already consumed roughly half of it. That makes 28 October a market event, as investors judge whether the Chancellor rebuilds the buffer or runs with less.

Then look at the pound. Higher yields normally pull in foreign money and lift a currency. Not this time: cable, as traders call GBP/USD, has hovered near its lowest since 26 June, around 1.32.

Analysts say UK yields are high for the wrong reasons. When bonds sell off on worries about fiscal credibility rather than on growth optimism, investors demand a bigger term premium and the currency gets no help. Rising yields with a weak pound are a warning sign, not a buying signal.

The obvious comparison is September 2022, when unfunded tax cuts in the mini-budget sent the 30-year yield up about 130 basis points in three days. Pension funds running leveraged liability-driven investment strategies faced collateral calls: demands for more cash as gilt prices fell. They sold gilts to raise it, pushing yields higher still, until the Bank of England stepped in to buy.

Yields are higher today than at the 2022 peak of about 5.1%, but the anatomy is different. The drivers cited now are global and inflation-driven, and the fiscal test is a Budget still to come rather than one already delivered. Forced selling isn’t among the causes being blamed, and regulators have since required LDI funds to hold much larger buffers against yield spikes.

The Bank of England, meanwhile, has already removed one source of selling. On 17 September it held Bank Rate at 3.75% on a 6–3 vote and paused all active gilt sales under quantitative tightening until April 2027. It is consulting the government on selling gilts directly to the Debt Management Office. Gilt yields and the pound fell that day, but two weeks later the 10-year hit its highest since 2007 anyway.

The Budget on 28 October is the catalyst. A credible plan to rebuild headroom could calm the long end; a Budget that leans on thin margins could add to the premium investors demand to hold gilts.

Watch the pound around 1.32. If sterling keeps sliding while yields rise, markets are charging a UK-specific risk premium; a pound that rises with yields would point to a calmer, rates-driven story.

Watch the global drivers too. With US 10-year yields near 24-year highs and energy-driven inflation risk from the Iran war still in play, gilts are unlikely to find a floor on their own. And watch the Bank of England: markets expect tighter policy, and the future of its gilt sales hangs on the consultation with the government.