Wall Street stocks fell early Tuesday with tech shares hit hard as Treasury Secretary Janet Yellen urged Congress to quickly raise the debt ceiling to keep the US government operating.

In a letter to lawmakers, Yellen warned that the government would run out of cash by around October 18 unless Congress raises the borrowing limit.

The warning comes amid intense partisan fighting over President Joe Biden’s agenda.

Both Yellen and Federal Reserve Chair Jerome Powell are slated to testify later Tuesday before Congress. Powell, who has signaled a possible tapering of stimulus spending as soon as this year, has also endorsed raising the debt ceiling.

About 20 minutes into trading, the Dow Jones Industrial Average was down 0.6 percent to 34,667.22.

The broad-based S&P 500 dropped 1.1 percent to 4,396.58, while the tech-rich Nasdaq Composite Index tumbled 1.7 percent to 14,718.52.

Analysts attributed the disproportionate declines in tech names to rising treasury yields. Higher interest rates generally hit tech companies more than some other businesses because of their greater reliance on debt to fund growth.

Among individual companies, Ford shot up 2.8 percent after announcing $11.4 billion in new investments in electric vehicle production.