X0508 4 2025-07-01 0001743907 Sun Country Airlines Holdings, Inc. SNCY 0001850697 Trousdale William C/O SUN COUNTRY AIRLINES HOLDINGS, INC. 2005 CARGO ROAD MINNEAPOLIS MN 55450 1 Interim CFO and SVP 1 Common Stock, par value $0.01 per share 2025-07-01 4 S 0 442 11.7568 D 27989 D Common Stock, par value $0.01 per share 2025-07-02 4 S 0 996 12.21 D 26993 D Represents the number of shares sold by the reporting person to cover tax withholding obligations in connection with the vesting of restricted stock units. This sale is mandated to satisfy the tax withholding obligations which are funded by a "sell to cover" transaction and does not represent a discretionary trade by the reporting person. This sale was effected pursuant to a Rule 10b5-1 trading plan. The 10b5-1 trading plan was adopted on September 12, 2024. /s/ Rose Neale, attorney-in-fact for William Trousdale 2025-07-03