US stocks open lower as PacWest woes offset Fed optimism

US stocks opened lower on Thursday after PacWest Bancorp's move to explore strategic options deepened concerns about the health of regional banks, countering optimism from the Federal Reserve signaling a likely pause in interest rate hikes.

The Dow Jones Industrial Average fell 66.46 points, or 0.20%, at the open to 33,347.78. The S&P 500 opened lower by 8.20 points, or 0.20%, at 4,082.55, while the Nasdaq Composite dropped 27.99 points, or 0.23%, to 11,997.34 at the opening bell.