5 things to know before the stock market opens Monday

• The U.S. joined Israel’s war against Iran, striking three nuclear sites.
• Stock futures were little changed and oil was barely higher, as traders watched Iran’s reaction.
• U.S. health insurers are taking steps to speed up and reduce prior authorizations, which are often a headache for both patients and providers.

Here are the most important news items that investors need to start their trading day:

1. Muted markets

Stock futures were mostly unchanged Monday after the U.S. joined Israel’s war against Iran. The U.S. carried out strikes against three Iranian nuclear sites, leading to fears of a wider conflict in the Middle East. Even so, the effects on financial markets were muted Monday. Oil prices were barely higher, giving up an earlier jump following the attacks. The escalation in the conflict adds to uncertainty around stocks, and follows two straight losing weeks for the S&P 500. Investors will be watching Iran’s reaction to gauge how the conflict could unfold. Follow live market updates.

2. An escalation

President Donald Trump said after the strikes that “there will be either peace, or there will be tragedy for Iran far greater than we have witnessed” since Israel first targeted the country’s nuclear sites. Iran called the attacks “outrageous” and argued the U.S. and Israel had stifled efforts to reach a diplomatic agreement over the country’s nuclear program. Iran and Israel both launched new strikes on the other over the weekend. Iran’s Foreign Minister Abbas Araghchi is heading to ally Russia to discuss the conflict Monday, though it’s unlikely Moscow will provide a significant supply of weapons as it fights its war in Ukraine.

3. The oil outlook

As oil prices gave up gains Monday, traders appeared to be betting the widening of the conflict would not cut off oil supply. While Iran said it reserves “all options” to respond to the U.S. attacks, a move to close the Strait of Hormuz could prove the most disruptive for markets. Iran’s parliament reportedly voted to close the critical shipping route, though its national security council holds the final say. Still, analysts consider the move unlikely. The U.S. is urging China to prevent Iran from closing the strait.

4. Removing hurdles

Major U.S. health insurers said they will streamline an arduous process for approving some claims. They said the moves will help to speed up and reduce the number of prior authorizations, which make providers get insurers to sign off before they can administer certain care to patients. Among the changes, individual plans will cut down the number of claims subject to prior authorization by next year, while the insurers will set a common standard for submitting electronic authorization requests by 2027. The changes will apply to major insurers including CVS Health, UnitedHealthcare, Cigna, Humana and Blue Cross Blue Shield.

5. New hand at the wheel

Antonio Filosa, a 51-year-old Italian native, is stepping into his new role as CEO of Stellantis after spending weeks visiting the automaker’s plants in the U.S., Canada and Europe. Executives and employees inside and outside the company told CNBC that Filosa knows the business well, from the factory floor to the C-suite. But they also said he has his work cut out for him. The parent company for Jeep, Ram, Chrysler and other brands is dealing with self-inflicted challenges, including fractured relationships with employees and dealers, as well as broader economic concerns that are affecting the whole industry.

– CNBC’s Lisa Kailai Han, Brian Evans, Ruxandra Iordache, Spencer Kimball, Sam Meredith, Lim Hui Jie, Annika Kim Constantino, Michael Wayland and Michele Luhn contributed to this report.