The UK's benchmark FTSE 100 index declined 0.3% to 10,341 points in early Tuesday trading, pressured by a sharp sell-off in pharmaceutical giant GSK following its announcement of a $10.6 billion deal to acquire shares of U.S.-based drug developer Nuvalent. The move underscores GSK's strategic push into lung cancer therapies, but investors reacted cautiously, sending shares down 2.8%.
In contrast, the mid-cap FTSE 250 index managed a modest 0.2% gain, reflecting a mixed picture across the broader UK equity market. The divergence highlights ongoing sector-specific dynamics, with healthcare weighing heavily on the blue-chip index while other areas showed resilience.
Healthcare Sector Under Pressure
GSK's decline made it one of the largest drags on the FTSE 100, and the broader FTSE 350 Pharmaceuticals and Biotechnology index fell 1.6%, making it the worst-performing sector of the day. The proposed Nuvalent acquisition is part of GSK's efforts to bolster its oncology pipeline, particularly in lung cancer, but the market's reaction suggests concerns about the deal's price tag and integration risks.
Geopolitical and Macroeconomic Factors
Investor sentiment was also shaped by developments in the Middle East. Markets took note of signs of de-escalation after Iran and Israel reportedly halted attacks following an appeal from U.S. President Donald Trump, who hinted at a potential Iran deal within days. Despite the easing of tensions, inflation worries persisted, with higher energy costs linked to the conflict fueling expectations that the Bank of England could raise interest rates by 25 basis points in September, according to LSEG data.
Meanwhile, the UK government announced a £1.1 billion ($1.47 billion) initiative to expand domestic AI computing capacity, aiming to bolster the country's technological infrastructure and competitiveness in the rapidly evolving AI sector. This comes as UK indexes have lagged their Asian and U.S. counterparts, partly due to limited exposure to AI-related companies.
Individual Stock Movers
BP shares fell 1%, tracking weaker crude oil prices, as investor attention remained on the energy major following the departure of former chairman Albert Manifold. A recent report indicated that investors and former executives are still unclear about the circumstances surrounding his exit.
On the upside, venture capital firm Molten Ventures surged 9.5% after reporting its annual results, while Fever-Tree Drinks rose 6.4% after expressing confidence in meeting full-year market expectations for revenue and core profit, also announcing an increase in its share buyback programme. Homebuilder MJ Gleeson fell 3.5%, reflecting ongoing challenges in the housing sector.
The British pound strengthened against the U.S. dollar, with GBP/USD recovering above 1.3350 after touching a three-week low.
Construction Sector Faces Record Cost Inflation
Separate data from S&P Global highlighted mounting challenges in the UK construction sector. British construction firms experienced the sharpest month-on-month increase in cost inflation since records began in 1997, with the Construction Purchasing Managers' Index measure of input cost inflation rising to 70.5 in March from 59.5 in February—the highest level since November 2022. This follows similar trends in manufacturing, where cost burdens rose at the steepest monthly pace since October 1992.
Demand conditions also weakened, with new orders declining at the fastest pace since November last year. The headline construction PMI remained below the 50.0 expansion threshold for the fifteenth consecutive month, though it improved slightly to 45.6 in March from 44.5 in February, indicating a moderated pace of contraction. Official data showed construction output rose 0.2% in January after a 2% contraction in the final quarter of 2025, offering some stabilization but insufficient to offset broader headwinds.
For more market insights, see our coverage of Dow Slides 207 Points as Tech Selloff Intensifies and Gold Slides 1.5% as Oil Spike, Rising Yields Override Geopolitical Haven Demand.
This article is for informational purposes only and does not constitute financial advice.
