U.S. stocks tanked in the morning session on Thursday as investors are shocked by U.S. President Donald Trump's reciprocal tariff announcement.

The Dow Jones Industrial Average lost over 1,400 points, or 3.5 percent, to 40,747.76 as of 10:05 a.m. eastern time (1405 GMT). Meanwhile, the S&P 500 shed 218.81 points, or 3.86 percent, to 5,452.17. The Nasdaq Composite Index dropped by 796.85 points, or 4.53 percent, to 16,804.20.

Amid widespread opposition, Trump on Wednesday signed an executive order on the so-called "reciprocal tariffs," imposing a 10-percent "minimum baseline tariff" on all imports and higher rates on certain trading partners.