Historically renowned for seasonal volatility and sluggish returns, September 2026 fully lived up to its legacy. The key macroeconomic theme was a renewed inflation shock driven by elevated energy prices as the US-Israel conflict with Iran continued to disrupt the Middle Eastern energy market. Brent crude experienced extreme volatility throughout the month, ultimately surging by around 14% to settle in the $98 to $106 per barrel range. The persistence of higher energy prices reignited concerns that inflation could remain elevated for longer, placing significant pressure on major central banks to maintain or tighten their restrictive monetary policies.
The resulting spike in government bond yields represented the month’s defining market development. Global government bonds suffered one of their weakest months in years. The rise in long-term yields increased borrowing costs for governments, companies and households while simultaneously raising the discount rate applied to future corporate earnings, creating increased pressure for highly valued technology stocks.
United States
The US economy continued to display considerable resilience despite tighter financial conditions, though inflation pressures remained a core headwind. Annual inflation in August ticked up to 3.4% year on year, while core CPI rose 2.4%. Against this backdrop, the Federal Reserve delivered an interest rate hike at the September FOMC meeting, raising the federal funds rate by 25 basis points to a target range of 3.75%-4.00%. The Fed described economic activity as expanding at a solid pace, supported by resilient domestic spending, strong productivity growth and robust capital investment, while emphasising that inflation remained elevated.
Treasury yields surged to their highest levels since the financial crisis, with the benchmark 10-year note yield reaching 5.2297% before settling at 5.158%, while the 30-year bond yield touched 5.5319%, the highest since 2004. This has created a difficult environment for high-growth and technology stocks where valuations remain dependent on expectations of strong future earnings.
US equities remained comparatively resilient despite the bond market turmoil buoyed by continued enthusiasm for AI-related investments. However, investor caution was evident in fund flows, with US equity funds recording four consecutive weeks of outflows totalling $31.44 billion. By the end of the month, the S&P 500 remained more than 12% higher for the year, illustrating that September’s weakness represented a relatively modest setback against the broader 2026 advance.
United Kingdom
The UK entered September with a complex inflation and growth outlook. The CPI inflation increased to 3.1% in August from 2.9% in July. The Bank of England’s Monetary Policy Committee voted 6-3 to maintain the Bank Rate at 3.75% at its September meeting, although three members preferred a 25-basis-point increase. The Bank warned that the Middle East conflict had pushed crude and refined energy prices higher and that inflation was likely to rise further in the coming quarters.
UK financial markets reflected the global rise in yields and renewed inflation risks. The FTSE 100 displayed relative stability due to its heavy exposure to energy producers, financial and defensive value companies. Nevertheless, rising gilt yields and weaker expectations for monetary easing limited broad-market capital appreciation. The Sterling was also under pressure against the US dollar alongside other European currencies as markets priced in elevated import energy bills and tighter credit conditions.
Eurozone
The Eurozone also experienced a similar combination of stronger-than-expected economic activity and renewed inflationary pressure. Inflation, however, moved in the wrong direction. Euro area headline inflation accelerated to 3.2% in August from 2.9% in July, driven primarily by energy components.
In response the European Central Bank raised its key interest rates by 25 basis points at its September meeting. The ECB projected headline inflation at 3.0% for 2026 and 2.5% for 2027, while forecasting GDP growth of 0.9% in 2026 and 1.4% in 2027. The combination of stronger activity and persistent energy inflation has therefore complicated the outlook for monetary policy.
The Governing Council cited heightened inflation risks and supply disruptions stemming from the Middle East conflict continued to generate inflationary pressures expected to keep inflation well above the 2% target for an extended period. A sharp spike in sovereign yields across core European economies like Germany and France elevated corporate debt financing costs for businesses and deepened economic growth concerns across the continent.
European equity benchmarks ended the month lower, with the pan-European STOXX 600 index declining 2.5% this month as higher borrowing costs and energy price volatility weighed heavily on cyclical and industrial valuations.
Japan
Japan’s economic backdrop in September stood out from its Western counterparts as the Bank of Japan continued to pursue its policy normalisation trajectory. The BOJ raised its policy rate by 25 bps to 1.25% in September, pushing domestic policy rates to their highest level in 31 years. The rate hike came amid rising inflation fuelled by Middle East tensions and yen volatility, which prompted coordinated currency intervention by Tokyo and Washington. Japan’s core inflation stood at 1.7% in August, down from 1.8% in July but remaining close to the BOJ’s target.
The 10-year Japanese Government Bond (JGB) yield breached multi-decade highs, approaching 3.0% as markets priced in further policy tightening. Following the Fed’s hawkish stance, the yen depreciated 2% against the US dollar, marking its weakest monthly performance in two years.
Japanese equities remained relatively strong outperforming Western markets despite the broader bond-market sell-off. The Nikkei 225 benefited from technology and semiconductor exposure, while financial stocks also gained from the prospect of higher domestic interest rates. Weakness in the yen offered ongoing support to domestic exporter revenues.
China
China presented a contrasting picture as inflation remained subdued, with CPI rising just 0.8% year on year in August. The People’s Bank of China (PBOC) maintained accommodative monetary policies and low policy rates to support domestic credit growth.
While property market sluggishness continued to weigh on broad domestic sentiment, targeted fiscal support and trade stabilization measures helped bolster manufacturing output. Bilateral trade negotiations produced a temporary tariff standstill between Washington and Beijing through January 10, including tariff reductions on $60 billion worth of traded goods, deepening efforts to inject some stability into relations between the powers. The tariff relief extended to an array of products, from US coal and agricultural products to made-in-China toys, car seats and holiday decorations.
Although underlying trade frictions remained unresolved, the temporary tariff rollbacks provided short-term relief to export-oriented industries. Chinese equities delivered mixed overall performance, as domestic structural adjustments offset gains in advanced manufacturing, high-tech supply chains, and Electric Vehicle (EV) sectors.
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Past performance is not an indicator of future performance.
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