X0306 4 2021-06-03 0 0001078075 NETSCOUT SYSTEMS INC NTCT 0001183333 BUA JEAN A C/O NETSCOUT SYSTEMS, INC. 310 LITTLETON ROAD WESTFORD MA 01886 0 1 0 0 EVP, CFO and Treasurer Common Stock 2021-06-03 4 M 0 7500 A 64879 D Common Stock 2021-06-03 4 F 0 2193 29.26 D 62686 D Restricted Stock Unit 2021-06-03 4 M 0 7500 D 2021-06-03 Common Stock 7500 67500 D Restricted Stock Unit 2021-06-04 4 A 0 27000 A Common Stock 27000 94500 D Performance Stock Unit 2021-06-04 4 A 0 18000 A Common Stock 18000 18000 D The shares of Common Stock were acquired upon the vesting of certain restricted stock units previously granted to the reporting person. The price is N/A. The shares of Common Stock were withheld to satisfy the reporting person's tax withholding obligation upon the vesting of restricted stock units. Represents the closing price of the Company's Common Stock on June 2, 2021. Date is N/A. The restricted stock units vest in four equal annual installments with the first installment vesting on June 3, 2022. The performance stock units shall vest in a range of 0% to 100% upon the determination of the Compensation Committee of the Board of the attainment of the required relative total shareholder return over the 36-month period commencing on June 4, 2021, and ending on June 3, 2024. /s/ Greg Sloan, by Power of Attorney 2021-06-07