JetBlue Airways forecast higher costs and unit revenue below analysts' expectations for the first quarter on Tuesday, sending the New York-based carrier's shares down 14% in morning trade.

Unit costs in 2025 will rise as much as 7% excluding fuel, the airline said Tuesday in a statement, outpacing analysts’ estimates on higher spending for compensation and aircraft maintenance. JetBlue shares fell as much as 18% as markets opened in New York, their biggest slump since Aug. 12.

JetBlue’s fourth-quarter results beat expectations, but the outlook for a key revenue metric was below forecasts.

JetBlue’s unit revenue guide implied deceleration year over year despite all the changes it has been making,” offered Melius Research analyst Conor Cunningham.