Stocks were lower at the halfway point Thursday in volatile trading, with the Dow Industrials down more than 1,000 points over two days. The S&P 500 fell more than a percent, while the Nasdaq fared slightly better.

The tech-heavy index saw fractional declines a day after a rout in tech stocks marked the worst market drop in eight months. Major tech companies like Microsoft ($MSFT), Facebook ($FB), and Alphabet ($GOOGL) had rebounded from Wednesday's losses with slight gains.

The continued sell-off was due in part to concerns about tightening monetary policy. President Trump has broken from tradition and repeatedly criticized the Fed for raising interest rates. He continued to attack Fed Chair Jerome Powell Thursday, saying he was "disappointed" in "far too stringent" rate hike decisions.

Earlier in the day, stocks briefly turned positive before extending their losses.