It seems as if something fundamentally changed in 2018, beginning a multi-year period of volatility.

From a WashPost article about the period: "DEC. 4, 2018
Markets tumbled after Trump tweeted “I am a Tariff Man” and the Trump administration backed off earlier claims of a trade-war truce with China." (washingtonpost.com/graphics/2018/business/stock-market-crash-comparison/)
tarifftradewarTrend AnalysistrumpVIX CBOE Volatility Index

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