Head of trading at ETX Capital Joe Rundle said traders' apparent appetite for risk reflected the view that, if resolved quickly, a government shutdown "will do little damage to the overall health of the U.S. economy."
Investors are also monitoring a separate battle in Washington to raise the debt ceiling, as failure to do so could leave the U.S. unable to pay its bills and hurt its credit rating.
Several economic releases are slated for Tuesday, with the Census Bureau due to publish its monthly report on construction spending, and the Institute for Supply Management monthly manufacturing report. Major automakers will issue their monthly sales reports throughout the day.
In corporate news, drugstore operator Walgreen (WAG)is set to release its quarterly results before the opening bell.