US stocks set for a continued dip at the open. Caterpillar weighs

Futures slightly lower
S&P 500 futures are down 4 points after an 11 point decline yesterday on late-day selling.
Shares of Caterpillar are lower after the company blamed global uncertainty for some sales softness. They lowered their full-year profit outlook to a range of $10.59 to $11.09, compared to the previous outlook which was at the low