London-listed equities have extended their outperformance versus the U.S. into 2026 after a stellar 2025 – but cracks are beginning to show as the war in Iran drags on. The FTSE 100 index, home to shares of the U.K.'s most valuable listed companies, has gained around 5.3% so far this year, putting it ahead of all three of Wall Street's major averages and building on its 2025 momentum. In 2025, the FTSE 100 surged 21.5%, outpacing all three of New York's biggest indexes. Alessandro Dicorrado,