U.S. stocks are drifting in tentative trading Thursday following a rocky week so far because of worries coming out of the bond market about the U.S. government’s debt.

The S&P 500 was down 0.09% in early trading, coming off a sharp loss that has it potentially heading for its worst week in two months. The Dow Jones Industrial Average was down 83.43 points, or 0.2%, as of 10:30 a.m. Eastern time, and the Nasdaq composite up bt 0.53%.

Treasury yields were holding a bit steadier in the bond market, which has been the epicenter of Wall Street’s action this week, but only after several sharp swings in the morning. Yields have been on the rise in part because of worries about the U.S. government’s spiraling debt.

The House of Representatives approved a bill early Thursday that would cut taxes and could add trillions of dollars to the U.S. debt.

Besides making it more expensive for the U.S. government to borrow to pay its bills, higher Treasury yields can also filter into the rest of the economy and make it tougher for U.S. households and businesses to get their own loans. Higher yields also discourage investors from paying high prices for stocks and other investments.

The yield on the 10-year Treasury climbed as high as 4.63% before the U.S. stock market opened for trading, before receding back to 4.59%. It was at 4.58% late Wednesday and just 4.01% early last month.

The House’s multitrillion-dollar spending bill, which aims to extend some $4.5 trillion in tax breaks from President Donald Trump’s first term while adding others, is expected to undergo some changes when it gets to the Senate for a vote.

The legislation also includes a speedier rollback of production tax credits for clean electricity projects, which sent shares of solar companies tumbling. Sunrun dropped 40%, Enphase Energy fell 16.5% and First Solar slid 4%.

Health care stocks were also falling early Thursday after the Centers for Medicare & Medicaid Services said it was immediately expanding its auditing of Medicare Advantage plans. UnitedHealth Group fell 1.4% and Humana was down 3.6%.

In stock markets abroad, indexes fell across Europe and Asia. France’s CAC 40 dropped 1.1%, Hong Kong’s Hang Seng fell 1.2% and South Korea’s Kospi slid 1.2% for some of the sharper losses.