President Trump stated in a CNBC interview that he does not favor a merger between United Airlines Holdings and American Airlines Group, expressing concerns about reduced competition in aerospace. He referenced a February pitch by United CEO Scott Kirby and warned that consolidation can lead to complacency among industry players.

Following the president’s remarks, Spirit Airlines shares jumped as much as 178% on the day, while shares of United Airlines and American Airlines both declined. Investors weighed the potential for government support for Spirit against the prospect of blocked consolidation between two major carriers.

Trump suggested the federal government consider stepping in to help Spirit Airlines, which is exploring offering an equity stake to the US government to avert liquidation. Transportation Secretary Sean Duffy plans to review the situation amid rising jet fuel prices from US-Iran tensions and heightened debate over industry consolidation.