Spirit Airlines warned in a Securities and Exchange Commission filing late Monday that it may not have enough cash to operate for the next 12 months, saying “substantial doubt exists” about its ability to continue as a going concern. The disclosure sent shares of parent company Spirit Aviation Holdings plunging as much as 42% to about $2.15 on Tuesday. The Florida-based budget carrier cited weak domestic leisure demand, excess industry capacity and mounting liquidity pressures for the warning. For the quarter ended June 30, revenue slipped to approximately $1.02 billion while the airline booked a net loss of about $246 million. Spirit also faces tighter requirements linked to roughly $795 million in post-restructuring debt and a credit-card processor that is demanding additional collateral before its contract expires on Dec. 31. Management said it is pursuing a range of “liquidity-enhancing measures,” including selling or leasing back aircraft and spare engines, disposing of real estate and excess airport gate capacity, and introducing a premium-economy product to lift yields. The company plans to furlough around 270 pilots and downgrade 140 captains beginning in October and November to align staffing with reduced flight schedules. The alarm comes just five months after Spirit emerged from Chapter 11 bankruptcy, a restructuring that followed the collapse of a proposed $3.8 billion merger with JetBlue and a rejected overture from Frontier. Having accumulated more than $2.5 billion in losses since 2020, Spirit now faces the prospect of a second bankruptcy filing—or potential liquidation—if it cannot secure fresh funds or materially improve results.