The longest-ever bull market for U.S. stocks ended Wednesday.

The downturn, marked by a 20% decline from the most recent high for the Dow Jones Industrial Average, heightens fears that the economic expansion that began following the financial crisis could also be on its last legs. Stocks have crumbled, oil prices have tanked and U.S. government bond yields have plumbed record lows in the face of the rapidly spreading coronavirus.

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