Global stock markets extended a severe plunge Monday, fueled by fears that U.S. tariffs would lead to a global economic slowdown. European and Asian shares saw dramatic losses, the leading U.S. index flirted with bear market territory in pre-market trading, and oil prices sagged. The massive sell-off in riskier assets at the start of the trading week follows President Donald Trump's announcement of sharply higher U.S. import taxes and retaliation from China that saw markets fall sharply Thursday and Friday. MORE: https://www.wthr.com/article/news/nation-world/world-stock-markets-plunge-again-as-trump-doubles-down-on-tariffs/507-6bd88da4-c81d-45ed-afa4-ba034c6f3848