X0508 4 2025-10-23 0 0001013857 PEGASYSTEMS INC PEGA 0001480560 Trefler Leon C/O PEGASYSTEMS INC. 225 WYMAN STREET, STE 300 WALTHAM MA 02451 0 1 0 0 Chief of Clients and Markets 0 Common stock 2025-10-23 4 M 0 30590 12.60 A 149389 D Common stock 2025-10-23 4 F 0 15725 63.40 D 133664 D Common stock 2025-10-23 4 S 0 14865 63.40 D 118799 D Stock Options 12.60 2025-10-23 4 M 0 30590 0 D 2017-03-09 2026-03-09 Common stock 30590 0 D Represents the weighted average of sale prices, ranging from $63.40 to $63.46. The individual has provided the Company, and undertakes to provide to the staff of the Security and Exchange Commission or any security holder of the Company, upon request, full information regarding the number of shares sold at each separate price. The share amounts and price data in this Form 4 have been restated to reflect a 2-for-1 forward stock split of Pegasystems Inc.'s common stock effectuated on June 20, 2025. This option vested as to 20% of the shares subject to the option on the Date Exercisable set forth in Table II and as to the remaining 80% of shares in equal quarterly installments over the following four years. /s/Kathryn Leach, Attorney-in-Fact for Leon Trefler 2025-10-27