Pharmaceutical stocks fell in premarket trading on Monday after Trump to sign an executive order to cut the prices of medicine.

Novo Nordisk fell 4.5%; Novartis fell 4%; AstraZeneca, Pfizer, Eli Lilly fell 3%; Merck, Johnson & Johnson fell 2%.

President Donald Trump on Sunday said he will sign an executive order to slash prescription-drug prices.

In a post on his Truth Social platform, Trump said the order, which will be signed at 9 a.m. Monday, will institute a "most favored nation" policy where the U.S. will pay the same price for prescription drugs and pharmaceuticals "as the nation that pays the lowest price anywhere in the world."

Trump claimed his order will "almost immediately" reduce prescription drug and pharmaceutical prices by 30% to 80%. Americans pay an average of about three times more for prescription drugs than do customers in other countries, a 2024 report found.

The post did not specify details on how the order would be carried out, or whether it will be limited to Medicare and Medicaid drug prices. Trump said the plan will save the U.S. trillions of dollars.

The plan could hit pharmaceutical companies hard, severely undercutting their revenues.