Analysts with ING financial group outlined four possible avenues for Iran: full escalation that also draws in other nations such as China or Russia; disruption of the Strait of Hormuz; active or passive support for terrorist attacks in the U.S. and Europe; or taking no action at all.

Oil prices surged 2.6 percent and U.S. stock futures fell after American airstrikes over the weekend targeted three Iranian nuclear facilities.

Energy was the worst-performing sector of the S&P 500, which rose 1%. U.S. oil futures fell 7.2%.