X0306 4 2015-05-12 0 0001379895 DYNEGY INC. DYN 0001236545 FLEXON ROBERT C 601 TRAVIS 14TH FLOOR HOUSTON TX 77002 1 1 0 0 President and CEO Common Stock 2015-05-12 4 P 0 20000 32.48 A 421871 D The price reported in Column 4 is the weighted average price. These shares were purchased in multiple transactions at prices ranging from $32.38 to $32.75, inclusive. The reporting person undertakes to provide to Dynegy Inc., any security holder of Dynegy, Inc. or staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth herein. Amount includes 35,093 restricted stock units that vest on October 29, 2015, 21,645 restricted stock units that vest on March 18, 2016, 38,211 restricted stock units that vest in two annual equal installments beginning on March 3, 2016, 60,261 restricted stock units that vest in three annual equal installments beginning on March 3, 2016 and 153,563 restricted stock units that vest on April 30, 2018. /s/ Heidi D. Lewis, Attorney-in-Fact 2015-05-14