World equities tumbled after U.S. President Donald Trump signed an executive order imposing steep tariffs on nearly 90 trading partners, including levies of 35% on Canadian goods, 50% on Brazilian items, 25% on Indian products and 20% on imports from Taiwan. The duties, which take effect on 7 August, raise the effective U.S. tariff rate to roughly 18% and intensified fears of a deeper global trade conflict. The tariff shock coincided with unexpectedly weak U.S. labour data. Non-farm payrolls increased by just 73,000 in July, while earlier months were revised sharply lower, heightening concern that the job market is losing momentum. Futures pricing showed the likelihood of the Federal Reserve cutting interest rates at its September meeting jumping to more than 80%. Against that backdrop, the S&P 500 sank 1.6% to 6,238.01, its sharpest one-day decline since 21 May. The Nasdaq Composite slid 2.24% to 20,650.13, and the Dow Jones Industrial Average fell 1.23%, or 542 points, to 43,588.58. The tech-heavy Nasdaq 100 shed 2%, marking its worst session since 21 April. The CBOE Volatility Index closed above 20 for the first time in six weeks. Amazon.com dropped 8.3% after cloud-computing growth missed expectations, making it the largest drag on all three major indexes. Bond markets rallied on safe-haven demand, pushing the 10-year Treasury yield down 16 basis points to 4.21%. The week-long sell-off left the S&P 500 down 2.36% since Monday and prompted investors to brace for heightened policy and market volatility through the rest of the summer.