US stocks plunged Wednesday after rating agency Fitch downgraded the US government's credit rating, citing fiscal and political instability.

The S&P 500 (^GSPC) dropped 1.3%, while the Dow Jones Industrial Average (^DJI) fell nearly 1%, or over 300 points. The tech-heavy Nasdaq Composite (^IXIC) slipped more than 2%.

The downgrade drew an angry response from the Biden administration, with the Treasury Department calling it "arbitrary" after the White House and Congress averted a debt default more than two months ago. Fitch spotlighted the US's growing levels of debt, as well as political instability — including the Jan. 6, 2021, insurrection on the Capitol — as factors in their decision.

With the downgrade top of mind, investors also geared up for another full day of earnings. CVS (CVS) and Kraft Heinz (KHC) were among the top names to report before the bell. PayPal (PYPL), Shopify (SHOP), Occidental Petroleum (OXY), Etsy (ETSY), and Robinhood (HOOD) are among those due after the bell.