SCHEDULE 13G/A 0001032235-25-000004 0001032235 XXXXXXXX LIVE 26 Common Stock, $.01 par value per share 09/30/2025 0001013857 Pegasystems Inc. 705573103 225 Wyman Street Ste 300 Waltham MA 02451 ALAN TREFLER X1 66165267.00 13032110.00 66165267.00 13032110.00 79197377.00 N 46.0 IN Sole voting and dispositive power consists of (1) 44,934,364 shares of Common Stock held by Mr. Trefler, individually; (2) 10,879,283 shares held by the Alan N. Trefler Grantor Retained Annuity Trust I of 2024, of which Mr. Trefler is the sole trustee; (3) 8,703,426 shares held by the Alan N. Trefler Grantor Retained Annuity Trust II of 2024, of which Mr. Trefler is the sole trustee; and (4) 1,648,194 shares that Mr. Trefler has the right to acquire within 60 days of September 30, 2025 through the vesting or exercise of equity compensation awards. Shared voting and dispositive power consists of (1) 10,876,525 shares held by the Alan N. Trefler Irrevocable Non-GST Trust of 2022, of which Daniel Sherman and Pamela Trefler are the trustees and of which Mr. Trefler has ability to appoint and remove trustees; (2) 84,000 shares held by the Trefler Foundation, of which Mr. Trefler is a trustee and shares voting and dispositive power over these shares, but has no pecuniary interest in these shares; and (3) 2,071,585 shares held by The Trefler 2025 Trust, of which Goldman Sachs Trust Company of Delaware is the administrative trustee and of which Mr. Trefler has ability to appoint and remove trustees and distribution advisors. Pegasystems Inc. 225 Wyman Street, Ste 300, Waltham, MA, 02451 Alan Trefler c/o Pegasystems Inc., 225 Wyman Street, Ste 300, Waltham, MA 02451 United States Y 79,197,377 shares 46.0 66,165,267 shares 13,032,110 shares 66,165,267 shares 13,032,110 shares Y N Y Y Y Y Y ALAN TREFLER /s/ Alan Trefler 11/12/2025