X0306 4 2018-05-07 0 0001068851 PROSPERITY BANCSHARES INC PB 0001136856 HOLMES NED S 55 WAUGH DRIVE, SUITE 1111 HOUSTON TX 77027 1 0 0 0 Common Stock 2018-05-07 4 S 0 5895 74.0144 D 153360 D Common Stock 2018-05-08 4 S 0 13159 74.2318 D 140201 D Common Stock 2018-05-08 4 S 0 30946 74.6353 D 109255 D Common Stock 2000 I By spouse Common Stock 115181 I By profit sharing plan Common Stock 8820 I As trustee of granchildren's trust Common Stock 48500 I As trustee of SSH trust for adult daughter Common Stock 27500 I As trustee of SSH trust for adult daughter Common Stock 3720 I By trust Common Stock 70070 I By limited partnership The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $74.00 to $74.06, inclusive. The reporting person undertakes to provide to Prosperity Bancshares, any security holder of Prosperity Bancshares, 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 ranges set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $73.70 to $74.58, inclusive. The reporting person undertakes to provide to Prosperity Bancshares, Inc., any security holder of Prosperity Bancshares, Inc., or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $74.39 to $74.86, inclusive. The reporting person undertakes to provide to Prosperity Bancshares, Inc., any security holder of Prosperity Bancshares, Inc., or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. /s/ Ned S. Holmes 2018-05-09