FTSE 100 Surges 2.5% as Global Markets Rally on US-Iran Ceasefire Deal
London's FTSE 100 index surged more than 2.5% on Wednesday, reaching 10,590 points, as global financial markets staged a broad relief rally following the announcement of a two-week ceasefire between the United States and Iran — a development that sent oil prices tumbling and eased fears of prolonged inflation.
The rally brought the FTSE 100 to its highest level since the conflict began in late February, though the index remains down approximately 2.4% since the start of the Iran war. The benchmark is still up 7.2% for the year and 34% over the past 12 months, reflecting the broader strength of UK equities heading into 2026.
Oil Prices Tumble
The most immediate market impact was felt in the oil market. Brent crude futures fell sharply by around 14.6% to $93.36 a barrel — their lowest level since mid-March — as investors priced in the prospect of the Strait of Hormuz reopening and global oil supplies resuming normal flows. The strait, through which roughly 20% of the world's oil passes, has been effectively closed since Iran imposed restrictions following the outbreak of hostilities in February.
The drop in oil prices eased concerns about UK inflation, which economists had forecast could reach 2.6% by the fourth quarter of 2026 if energy disruption continued. Lower energy costs also raised hopes that the Bank of England might have more room to consider interest rate cuts later in the year, having held rates at 3.75% in March.
Winners and Losers on the FTSE
The rally was broad-based, with a fifth of the FTSE 100 rising between 7% and 12%. Rolls-Royce Holdings and housebuilders including Barratt Redrow, Persimmon, and Berkeley Group Holdings were among the biggest gainers, as the improved economic outlook boosted confidence in long-term investment. British Airways owner International Consolidated Airlines Group (IAG) also bounced strongly on the prospect of lower fuel costs.
Banking stocks also benefited, with Lloyds Banking Group returning to its pre-conflict level and NatWest and Barclays posting solid gains. However, energy companies BP and Shell saw their shares dip as the oil price-led gains that had supported them during the conflict unwound.
Unilever was a notable underperformer, dipping as much as 3.6% after warning that 2026 sales growth would likely hit the bottom of its forecast range.
Analysts Urge Caution
Despite the euphoria, financial analysts cautioned that the rally was driven by relief rather than resolution. Nigel Green, chief executive of deVere Group, warned that the market's reaction was "misplaced" and "far too optimistic," noting that the ceasefire was conditional and time-limited. "The two-week window is not a permanent policy shift," he said, adding that the Strait of Hormuz remained under the influence of one of the conflict parties.
Stephen Innes of SPI Asset Management noted that markets had been given "breathing room" but highlighted the ongoing regional tensions, including continued Israeli strikes in Lebanon, which Iran argued violated the ceasefire agreement.
Why It Matters
For UK households and businesses, the ceasefire and the associated fall in oil prices offer a potential reprieve from months of rising energy bills. The Bank of England had been caught between weak economic growth — the UK economy expanded by just 0.1% in the final quarter of 2025 — and inflationary pressures from the energy shock. A sustained fall in oil prices could give policymakers more flexibility in the months ahead.
What's Next
Markets will be watching closely as US-Iran negotiations begin in Islamabad on 10 April. Any breakdown in talks or renewed escalation in Lebanon could rapidly reverse the oil price decline and reignite inflation concerns. The FTSE 100's performance in the coming days will be a key barometer of investor confidence in the ceasefire's durability.
Full market analysis is available at interactive investor's breakdown of the FTSE 100 ceasefire rally.
