X0306 4 2017-05-15 0 0000039263 CULLEN/FROST BANKERS, INC. CFR 0001119355 WESTON GRAHAM M 112 EAST PECAN STREET SUITE 125 SAN ANTONIO TX 78205 1 0 0 0 Common Stock, $0.01 par value 2017-05-15 4 P 0 11096 90.09 A 11096 I Shares held by Trout Capital, Ltd. Common Stock, $0.01 par value 2017-05-16 4 P 0 6500 90.61 A 17596 I Shares held by Trout Capital, Ltd. Common Stock, $0.01 par value 2017-05-16 4 P 0 4485 91.66 A 22081 I Shares held by Trout Capital, Ltd. The price in Column 4 is based on a weighted average price. The prices actually paid range from $89.80 to $90.50. The reporting person will provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares purchased at each price within the ranges set forth in footnotes (1), (3) and (4) to this Form 4. Mr. Weston is the sole owner of Knightsbridge, LC which is the general partner of Trout Capital, Ltd. The price in Column 4 is based on a weighted average price. The prices actually paid range from $90.09 to $90.96. The price in Column 4 is based on a weighted average price. The prices actually paid range from $91.09 to $91.93. /s/ Graham M. Weston 2017-05-17