X0306 4 2020-12-02 0 0001013857 PEGASYSTEMS INC PEGA 0001480560 Trefler Leon C/O PEGASYSTEMS INC. 1 ROGERS STREET CAMBRIDGE MA 02142 0 1 0 0 SVP, Global Customer Success Common Stock 2020-12-02 4 S 0 1759 127.92 D 10177 D Common Stock 2020-12-02 4 M 0 370 0.00 A 10547 D Common Stock 2020-12-02 4 F 0 165 129.97 D 10382 D Restricted Stock Unit 0.00 2020-12-02 4 M 0 370 0.00 D 2018-03-02 Common Stock 370 1847 D Sold pursuant to a pre-arranged stock trading program under Rule 10b5-1 of the Securities Exchange Act of 934, as amended. Represents the weighted average of the sale prices on December 2, 2020, ranging from $127.85 to $128.04. The individual has provided the Company, and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Company, upon request, full information regarding the number of shares sold at each separate price. Represents a 5% vesting on December 2, 2020. The original grant was 7,387 restricted stock units, with 20% vesting on March 2, 2018, and the remaining 80% vesting in equal quarterly installments over the remaining four years. Does not include shares of common stock subject to unvested restricted stock units and/or options awards. Each restricted stock unit represents the right to receive, following vesting, one share of the issuer's common stock. Once vested, shares of common stock are not subject to expiration. /s/ Donald L. Lancaster, Attorney-in-Fact for Leon Trefler 2020-12-03