Major US stock indexes opened lower on Thursday. Rising government bond yields hurt investor sentiment significantly. Retail giant Walmart reported a rare sales miss, disappointing many. The Dow Jones Industrial Average fell 81.8 points at the open. The S&P 500 and Nasdaq Composite also experienced declines.

The S&P 500 just triggered a bullish signal, barely.

Stock Market Today: The Dow Jones index drops Thursday on Trump's "Economic D-Day" threat on Iran. Walmart dives on earnings.