G10's ‘surprise' currency star could stumble as peers hike interest rates

• The BOE has held rates at 3.75% while markets price in high probability of rate hikes by the Fed and ECB in September, with central bank rate increases typically boosting their home currencies
• U.K. GDP grew 0.4% in Q2 following 0.6% in Q1, among the strongest performances in the G7, but the economy remains highly vulnerable to elevated oil and gas costs from the Iran conflict
• The October 28 budget is expected to include higher ancillary taxes and increased debt issuance to fund spending, with markets concerned about measures that could dampen growth while requiring more borrowing

Summary: British Pound Faces Pressure as Policy Divergence Emerges

The British pound, a surprise outperformer among G10 currencies, may face headwinds as its central bank maintains a dovish stance while peers prepare to tighten policy.

Performance Data

Sterling gained 1.6% against the dollar year-to-date, 2.8% versus the euro, and 4.9% against the yen, while remaining flat against the Canadian dollar and down 1.3% against the Swiss franc. The currency's strength followed resilient UK economic growth of 0.4% in Q2 after 0.6% in Q1, among the strongest performances among developed nations.

Policy Divergence

The Bank of England has held its key rate at 3.75% throughout the year despite inflation concerns from spiking oil and gas prices amid the Iran conflict. Market pricing shows low probability of a September rate hike by the BoE, contrasting sharply with high expectations for increases by the Federal Reserve (expected Wednesday) and European Central Bank (later this month). This divergence threatens to weaken sterling as rate hikes typically boost currencies.

Political Transition and Fiscal Risks

Following PM Keir Starmer's July 20 resignation, successor Andy Burnham has overseen rising UK borrowing costs—now at their highest since 1998—though this reflects a global trend. The October 28 budget presents a critical test, with analysts warning of political risk. Expected measures include higher ancillary taxes, potential mansion taxes, tighter pension relief, and increased debt issuance to fund spending ambitions.

Markets remain cautious about policies that could dampen growth while increasing borrowing requirements, particularly given the UK's vulnerability to energy price shocks and elevated fiscal pressures.