X0306 4 2018-04-09 1 0001379895 DYNEGY INC. DYN 0001428577 Freeland Clint 601 TRAVIS 14TH FLOOR HOUSTON TX 77002 0 1 0 0 EVP and CFO Common Stock 2018-04-09 4 D 0 102056 D 0 D Common Stock Option (Right to Buy) 18.70 2018-04-09 4 D 0 70215 D Common Stock 70215 0 D Common Stock Option (Right to Buy) 23.10 2018-04-09 4 D 0 33784 D Common Stock 33784 0 D Common Stock Option (Right to Buy) 23.03 2018-04-09 4 D 0 34899 D Common Stock 34899 0 D Common Stock Option (Right to Buy) 27.24 2018-04-09 4 D 0 34943 D Common Stock 34943 0 D Common Stock Option (Right to Buy) 11.05 2018-04-09 4 D 0 58768 D Common Stock 58768 0 D Common Stock Option (Right to Buy) 8.02 2018-04-09 4 D 0 60647 D Common Stock 60647 0 D Restricted Stock Units 2018-04-09 4 D 0 94161 0 D Common Stock 94161 0 D Disposed of pursuant to the closing of the merger on April 9, 2018 (the "Effective Date") between Issuer and Vistra Energy Corp. (the "Merger") in exchange for 0.652 shares of Vistra Corp. stock having a market value of $20.83, closing price, per share on the Effective Date of the Merger. This option was assumed by Vistra Corp. in the Merger and replaced with an option to purchase 615,780 shares of Vistra common stock for $28.68. The option will expire pursuant to the terms of the grant agreement. This option was assumed by Vistra Corp. in the Merger and replaced with an option to purchase 22,027 shares of Vistra common stock for $35.43. The option will expire pursuant to the terms of the grant agreement. This option was assumed by Vistra Corp. in the Merger and replaced with an option to purchase 22,754 shares of Vistra common stock for $35.32. The option will expire pursuant to the terms of the grant agreement. This option was assumed by Vistra Corp. in the Merger and replaced with an option to purchase 22,782 shares of Vistra common stock for $41.78. The option will expire pursuant to the terms of the grant agreement. This option was assumed by Vistra Corp. in the Merger and replaced with an option to purchase 38,316 shares of Vistra common stock for $16.95. The option will expire pursuant to the terms of the grant agreement. This option was assumed by Vistra Corp. in the Merger and replaced with an option to purchase 39,541 shares of Vistra common stock for $12.30. The option will expire pursuant to the terms of the grant agreement. Restricted Stock Units convert into common stock on a one-for-one basis. Disposed of pursuant to the Merger in exchange for 0.652 shares of Vistra Restricted Stock Units having a market value of $20.83, closing price, per share on the Effective Date of the Merger. The Restricted Stock Units will vest pursuant to the terms of the Grant Agreements. /s/ Heidi D. Lewis, Attorney-in-Fact 2018-04-11