Brian Levitt, Global Market Strategist at Invesco, says the market is "recalibrating for a weaker economic backdrop."
Investors are getting spooked by the rising numbers of COVID-19 cases as the delta variant spreads across the globe.
The Dow fell about 725 points Monday, a drop of 2.1%. The S&P 500 ended the day down 1.6% and the Nasdaq was 1.1% lower.
This was the worst day for the Dow since a 943-point drop in late October, and it was the biggest decline this year. But the blue chip market barometer has had several even bigger point plunges since the start of 2020 due to concerns about the COVID-19 pandemic.