Business Combination Prospectus (Form 425)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF

THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): January 20, 2026

NICOLET BANKSHARES, INC.

(Exact name of registrant as specified in its charter)

Wisconsin

001-37700

47-0871001

(State or other jurisdiction of incorporation)

(Commission File Number)

(IRS Employer Identification No.)

111 North Washington Street

Green Bay, Wisconsin 54301

(Address of principal executive offices)

(920) 430-1400

(Registrant's telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

			☒			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

			☐			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

			☐			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

			☐			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class			Trading Symbol(s)			Name of each exchange on which registered
Common stock, par value $0.01 per share			NIC			New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter.)

Emerging Growth Company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02			Results of Operations and Financial Condition.

On January 20, 2026, Nicolet Bankshares, Inc. ("Nicolet") announced its earnings for the quarter and year ended December 31, 2025. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Pursuant to General Instruction B.2 of Form 8-K, the information in this Item 2.02 and Exhibit 99.1, is being furnished to the Securities and Exchange Commission and shall not be deemed to be filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities under that Section. Furthermore, the information in this Item 2.02 and Exhibit 99.1, shall not be deemed to be incorporated by reference into Nicolet's filings under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 7.01			Regulation FD Disclosure.

On January 20, 2026, Nicolet declared a quarterly cash dividend of $0.32 per share on its common stock. The dividend will be payable March 16, 2026, to shareholders of record as of March 2, 2026. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

The information in Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1 furnished herewith, is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or the Exchange Act, or otherwise subject to the liabilities of such section. The information in this report on Form 8-K shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Securities Act, or under the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Item 8.01			Other Events.

The only information in this Current Report on Form 8-K that is being filed in compliance with Rule 425 of the Securities Act, as amended, is the information contained in the portions of the press release filed herewith as Exhibit 99.1 that relate solely to the proposed merger between Nicolet Bankshares, Inc. and MidWestOne Financial Group, Inc.

Item 9.01			Financial Statements and Exhibits.

Exhibit No.						Description of Exhibit
99.1						Press Release, dated January 20, 2026
104						Cover Page Interactive Data File - the cover page XBRL tags are embedded within the Inline XBRL document

Signatures

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date:

January 20, 2026

NICOLET BANKSHARES, INC.

By:

/s/ H. Phillip Moore, Jr.

H. Phillip Moore, Jr.

Chief Financial Officer