Frankfurt's DAX 40 fell more than 2% on Monday, sliding to a three-week low near 24,720 as investors weighed the economic implications of the escalating conflict in the Middle East. Over the weekend, tensions surged after the United States and Israel launched coordinated strikes in Iran that killed Supreme Leader Ayatollah Ali Khamenei and other senior Iranian officials, prompting a swift retaliatory response from Tehran. Travel and leisure stocks, particularly airlines, led the declines, with Deutsche Lufthansa dropping more than 5%.