X0306 4 2019-08-21 0001436126 Mistras Group, Inc. MG 0001473727 Vahaviolos Sotirios J. C/O MISTRAS GROUP, INC. 195 CLARKSVILLE ROAD PRINCETON JUNCTION NJ 08550 1 1 1 Executive Chairman Common Stock 2019-08-21 4 M 0 133461 13.46 A 10478110 D Common Stock 2019-08-21 4 F 0 61191 15.66 D 10416919 D Common Stock 2019-08-21 4 F 0 47220 15.67 D 10369699 D Stock Options (Right to Buy) 13.46 2019-08-21 4 M 0 133461 0 D 2019-09-01 Common Stock 133461 816539 D Stock Options (Right to Buy) 13.46 2019-08-21 4 F 0 816539 0 D 2019-09-01 Common Stock 816539 0 D Represents shares withheld for payment of tax liability as a result of the exercise of stock options. Represents shares withheld for payment of additional tax liability as a result of the exercise of stock options on August 16, 2019 which were not originally withheld upon exercise. These options are fully vested. These options were surrendered to the issuer as consideration for the exercise price for the net cashless exercise of 950,000 stock option. Michael C. Keefe, attorney-in-fact for Sotirios J. Vahaviolos 2019-08-23