Stock futures ticked lower before markets reopened Friday morning amid uncertainty among investors over the Middle East and whether the United States was about to get directly involved in the Israel-Iran conflict.

Defense stocks, already lifted by Russia's conflict with Ukraine, have made modest gains since Israel launched its attacks. The S&P 500 Aerospace and Defense index hit record highs early last week in the culmination of a rebound of over 30% from losses in the wake of Trump's April 2 "Liberation Day" tariff announcements.

The S&P 500 typically fully recovers within a few weeks of a major geopolitical shock such as an invasion or attack, Deutsche Bank Research found.