U.S. stocks are slipping on Tuesday following signals that one of the U.S. economy's main engines, spending by households, is weakening while Israel's conflict with Iran may be worsening.

The S&P 500 was 0.4% lower in early trading. The Dow Jones Industrial Average was down 129 points, or 0.3%, as of 9:35 a.m. Eastern time, and the Nasdaq composite was 0.4% lower.