FTSE 100 Falls 0.49% as U.S.-Iran Tensions Escalate; AstraZeneca Slumps After Late-Stage Trial Failure

The FTSE 100 traded lower on Thursday, July 9, 2026, down roughly 0.5% during the morning session. AstraZeneca shares plunged as much as 9.55%, wiping out nearly £19 billion in market value. That single stock drove almost all of London’s underperformance versus other European indices. Germany’s DAX gained 0.4%, while France’s CAC 40 rose 0.45% during the same session. U.S. Central Command also confirmed fresh overnight strikes on roughly 90 Iranian military targets. Here’s what’s driving both the AstraZeneca selloff and today’s FTSE 100 weakness.

Why The FTSE 100 Underperformed European Peers Today

The FTSE 100 (^FTSE) stood alone in negative territory while other major European indices advanced Thursday. Spain’s IBEX gained 1%, and Italy’s FTSE MIB rose 0.8% during morning trading. The pan-European Stoxx 600 index climbed 0.4%, cushioned by broader technology sector gains.

• FTSE 100: down approximately 0.5% during Thursday’s session
• Germany’s DAX: up 0.4%
• France’s CAC 40: up 0.45%
• Pan-European Stoxx 600: up 0.4%

This divergence confirms today’s FTSE 100 weakness was company-specific, not driven by broader European sentiment. AstraZeneca alone explains why London’s benchmark lagged its continental counterparts so significantly.

Middle East Tensions Add Background Pressure

U.S. Central Command confirmed a second consecutive night of strikes on Iranian military infrastructure. Targets included air defense systems, missile storage facilities, and naval installations along Iran’s coastline. Wednesday’s session had already seen the FTSE 100 tumble 1.66% to 10,489.04.

💥Last night, US forces launched another strike on Iran, hitting approximately 90 military targets, according to CENTCOM.

This included air defense systems, coastal surveillance assets, missile and drone depots, naval facilities, and military logistics infrastructure along the… pic.twitter.com/ZGvtuYUJFc

— News.Az (@news_az) July 9, 2026

Oil prices actually eased Thursday slightly, with Brent crude slipping 0.9% as markets judged escalation contained. That cooling in crude prices offered some relief after Wednesday’s sharper geopolitical-driven selloff across UK equities.

AstraZeneca’s Wainua Trial Failure Explained

AstraZeneca’s Wainua, developed with U.S. partner Ionis, failed its Phase III CARDIO-TTRansform trial this week. The study tested Wainua in patients with transthyretin-mediated amyloid cardiomyopathy, a rare heart condition. Results showed no statistically significant reduction in cardiovascular deaths or recurrent events versus placebo.

• Trial name: CARDIO-TTRansform
• Condition studied: transthyretin-mediated amyloid cardiomyopathy (ATTR-CM)
• Study duration: up to 140 weeks
• Partner: Ionis Pharmaceuticals

Citi had modeled peak Wainua sales near $6.2 billion, assigning it a 59% probability of success. That made this the bank’s highest-conviction late-stage readout among AstraZeneca’s three key 2026 trial catalysts.

How Much Value AstraZeneca Lost

AstraZeneca shares (NYSE: AZN) fell between 8.6% and 9.55% across different trading snapshots Thursday morning. That decline erased approximately £19 billion to £20 billion from the company’s market capitalization. AstraZeneca’s market cap fell below £200 billion, still ranking second-largest on the FTSE 100, behind HSBC. Citi had estimated the trial carried roughly 2% to 2.8% of the company’s net present value.

Jefferies analyst Michael Leuchten called the failure surprising, noting management had expressed strong confidence beforehand. He suggested the share reaction could exceed the direct financial impact due to credibility concerns.

Other Notable FTSE 100 And FTSE 250 Movers

Not every stock fell alongside AstraZeneca during Thursday’s session on the London Stock Exchange. Computacenter shares jumped roughly 11% to 13% after raising its full-year profit outlook. The technology and services provider expects adjusted pre-tax profit to nearly double year-on-year.

• Computacenter: up 11% to 13% on stronger trading guidance
• Playtech: up over 17% on strong first-half trading update
• Miners including Antofagasta and Glencore: up more than 3%
• Capita: shares slid on pension scheme cost warnings

This mixed picture shows Thursday’s FTSE 100 weakness stemmed from one major constituent, not broad selling. Investors rotated into strength elsewhere across technology, gaming, and mining stocks simultaneously.

Final Thoughts

The FTSE 100’s decline Thursday reflects AstraZeneca’s near-9% plunge following its Wainua trial failure. Broader European indices gained, confirming this weakness stayed largely isolated to one heavyweight constituent. Middle East tensions remain a background risk, though oil prices actually eased slightly during today’s session. Investors tracking AstraZeneca, Computacenter, and the FTSE 100 broadly should watch AstraZeneca’s Q2 earnings on July 27, 2026.

Disclaimer:

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