X0306 4 2020-11-10 0 0001078075 NETSCOUT SYSTEMS INC NTCT 0001232878 DOWNING JOHN C/O NETSCOUT SYSTEMS, INC. 310 LITTLETON ROAD WESTFORD MA 01886 0 1 0 0 EVP, World-Wide Sales Common Stock 2020-11-10 4 S 0 5000 22.0888 D 97616 D The shares of Common Stock were sold pursuant to a 10b5-1 plan. The shares sold on this date were sold in multiple transactions. This price is the weighted average sales price per share; the actual sales price per share ranged from $21.95 to $22.28. The reporting person undertakes to provide to NetScout Systems, Inc., any security holder of NetScout Systems, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (2) to this Form 4. /s/ John Downing 2020-11-12