US stock markets today (March 20, 2026): S&P 500, Dow, Nasdaq slip as bond yields rise; crude oil prices steady amid Iran war

The S&P 500 declined 0.5% in morning deals and was headed toward its longest losing streak in a year. The Dow Jones Industrial Average dropped 126 points, or 0.3%, while the Nasdaq Composite slipped 0.8% as of 9:35 am Eastern Time.Market sentiment remained weighed down by a further rise in Treasury yields, which increases borrowing costs for companies and households and tends to pressure valuations across asset classes. Growing uncertainty over inflation has also reshaped expectations around US monetary pol ...