The Dow Jones Industrial Average .DJI fell 69.3 points, or 0.13%, at the open to 53,663.11.
The S&P 500 .SPX rose 4.9 points, or 0.06%, at the open to 7,790.68.
The Nasdaq Composite .IXIC rose 55.5 points, or 0.21%, to 26,784.652 at the opening bell.
Markets open subdued amid Middle East tensions
The S&P 500 opened subdued on Monday as markets weighed the prospect of renewed tensions between the U.S. and Iran, while the report of a strong revenue forecast from AI lab Anthropic lifted some tech stocks.