The S&P 500 and Dow Jones indexes opened higher on Thursday, boosted by Boeing shares as the planemaker resumed production of its 737 MAX jets, but simmering tensions between the United States and China kept investors on edge.

The Dow Jones Industrial Average rose 149.09 points, or 0.58%, at the open to 25,697.36, and the S&P 500 opened higher by 10.48 points, or 0.35%, at 3,046.61. But the Nasdaq Composite dropped 19.36 points, or 0.21%, to 9,392.99 at the opening bell.