In the UK government bond market, a popular trading strategy signals that investors are confident in Prime Minister Andy Burnham's commitment to controlling government borrowing. With less than three months until the new government's first budget, the asset swap spread—a widely watched gauge of anxiety over bond supply—remains stable.

JPMorgan, a major market maker in UK interest rates, notes this indicates investors are betting that Burnham will follow through on his words. Julian Baker, co-head of linear rates trading for Europe, the Middle East, and Africa at JPMorgan, stated that betting on UK gilts outperforming equivalent maturity swaps has become a "much sought-after trading strategy." Strategists from Bank of America, Morgan Stanley, and RBC Capital Markets have also highlighted the popularity of this trade in recent interviews and research notes.

Baker said: "The government is currently sending signals of fiscal responsibility, and the market will expect them to match their words with actions." The asset swap trade essentially measures the difference between bond yields and swap rates, which is attractive to investors who want exposure to gilts without taking on too much bond market risk. Currently, the spread is negative because bond prices are lower than swap rates; however, if the government delivers a responsible budget that avoids a significant increase in debt issuance, boosting bond prices, the spread could converge towards zero.

Fabio Bassanin, UK strategist at Morgan Stanley, commented: "The trade should remain an attractive way to maintain a bullish UK duration exposure." So far, Burnham's proposed policies have been relatively moderate, and he has committed to following the government's fiscal rules, which has somewhat eased market concerns about a surge in large-scale bond issuance. His plans include further devolution, establishing a prime minister's office in Manchester, capping bus fares, and reducing VAT on electricity bills by about £45 ($61) per household during winter.

Fiscal Concerns Remain

However, uncertainty persists over how the prime minister will fund his ambitious decade-long agenda, whether through tax increases or more borrowing. If the October budget disappoints, this widely popular asset swap trade could trigger a massive exodus of funds, potentially impacting banks, hedge funds, and institutional investors. James Lynch, portfolio manager at Aegon Asset Management, noted: "These types of trades do tend to be popular around fiscal events." However, he is not currently participating in the asset swap trade and added: "I want to see where the market water level is before Burnham's first budget."

Market tension was evident in late July. At that time, while Burnham insisted he would adhere to the government's self-imposed borrowing and spending constraints, his incidental mention of seeking "fiscal flexibility" within the rules triggered a brief sell-off in UK gilts, pushing the 30-year gilt yield to 5.8%, its highest level since mid-May. This scene is reminiscent of the surge in yields after former Prime Minister Liz Truss announced unfunded tax cuts in 2022.

Currently, the UK 30-year swap spread remains near the middle of its range this year, roughly in line with the year-to-date average. Megum Muhic, UK rates strategist at RBC Capital Markets, pointed out that while caution is necessary, the asset swap strategy has been "quite popular recently" given the spread level it offers. She stated that the budget announcement date of October 28th "will undoubtedly be a major independent catalyst for the gilt market."