X0508 4 2026-03-05 0001174850 NICOLET BANKSHARES INC NIC 0001253903 ATWELL ROBERT BRUCE C/O NICOLET NATIONAL BANK 111 NORTH WASHINGTON STREET GREEN BAY WI 54301 1 0 Common Stock 2026-03-05 4 M 0 10000 56.43 A 44054 D Common Stock 2026-03-05 4 F 0 6669 151.93 D 37385 D Common Stock 2026-03-05 4 S 0 2815 150.52 D 34570 D Common Stock 2026-03-05 4 S 0 400 151.34 D 34170 D Common Stock 2026-03-05 4 S 0 116 152.05 D 34054 D Common Stock 554.562 I by Nicolet National Bank Deferred Compensation Plan For Non-employee Directors Stock Option (Right to Buy) 56.43 2026-03-05 4 M 0 10000 0 D 2027-11-01 Common Stock 10000 57500 D The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $149.795 to $150.920, inclusive. Mr. Atwell undertakes to provide to Nicolet Bankshares, Inc., any security holder of Nicolet Bankshares, Inc., or the staff of the Securities and Exchange Commission upon request, full information regarding the number of shares at each separate price within the range set forth in footnote (1) to this Form 4. The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $150.960 to $151.790, inclusive. Mr. Atwell undertakes to provide to Nicolet Bankshares, Inc., any security holder of Nicolet Bankshares, Inc., 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 footnote (2) to this Form 4. The nonqualified options vested in five annual installments of 13,500 shares on November 1 of each year, beginning on November 1, 2018, and fully vested on November 1, 2022. The nonqualified options are currently exercisable as to 57,500. /s/ H. Phillip Moore, Jr., as attorney-in-fact for Robert B. Atwell 2026-03-09