FirstSun Capital Bancorp (FSUN) sets Castle Creek board seat and director exit terms

Rhea-AI Filing Summary

FirstSun Capital Bancorp filed an amended current report to correct the signature date on a prior disclosure about a new board representation arrangement and related governance changes. The company entered into a Board Representative Letter Agreement with Castle Creek Capital Partners IX, LP on December 3, 2025. Beginning with the earlier of the closing of FirstSun’s proposed merger with First Foundation Inc. or the 2026 annual shareholders meeting, FirstSun will use its best efforts to place a Castle Creek designee on its board and recommend that nominee to stockholders. Castle Creek also may appoint a nonvoting board observer when it has no board representative, with these rights continuing while it holds at least 40% of its current share position. On the same date, director Isabella Cunningham notified the company she will resign effective at the earlier of the merger closing or the 2026 meeting, and FirstSun plans to maintain board size to accommodate Castle Creek’s nominee.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

(Amendment No. 1)

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (date of earliest event reported): December 3, 2025

FIRSTSUN CAPITAL BANCORP

(Exact name of registrant as specified in its charter)

Delaware			001-42175			81-4552413
(State or other jurisdiction of incorporation or organization)			(Commission File Number)			(I.R.S. Employer Identification Number)

1400 16th Street, Suite 250

Denver, Colorado 80202

(Address of principal executive offices and zip code)

(303) 831-6704

(Registrant’s telephone number, including area code)

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, $.0001 Par Value

FSUN

Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17CFR § 230.405) or 12b-2 of the Exchange Act of 1934 (17 CFR § 240.12b-2).

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. ☐

Explanatory Note

This Current Report on Form 8-K/A (the “Amendment”) of FirstSun Capital Bancorp (the “Company”) amends the Current Report on Form 8-K filed by the Company on December 4, 2025 (the “Original Report”). The sole purpose of the Amendment is the insertion of the correct date for the signature in the Original Report. No other revisions have been made to the Original Report.

Item 1.01    Entry into a Material Definitive Agreement.

Entry into Board Representative Letter Agreement

On December 3, 2025, FirstSun Capital Bancorp (the “Company”) entered into a Board Representative Letter Agreement with Castle Creek Capital Partners IX, LP (“Castle Creek”) that provides, beginning with the earlier of (i) the closing of the Company’s proposed merger with First Foundation Inc. (the “Proposed Merger Closing”) and (ii) the 2026 Annual Meeting of the Stockholders of the Company (the “2026 Annual Meeting”) the Company will use its best efforts to cause an individual designated for nomination by Castle Creek to be elected or appointed to the board of directors of the Company and will recommend to its stockholders the election of such individual designated at the applicable stockholders’ meetings of the Company. In addition, as of the date of the Board Representative Letter Agreement, to the extent Castle Creek does not have a board representative currently serving on the board of directors, Castle Creek may appoint an individual as a nonvoting observer to the board of directors. Such nomination and observer rights continue for so long as Castle Creek owns at least 40% of the total shares held by Castle Creek as of the date of the Board Representative Letter Agreement. The Board Representative Letter Agreement entered into with Castle Creek is substantially similar to the form of Board Representation Letter Agreements entered into with other stockholders of the Company as described in the Company’s Current Report on Form 8-K filed with the Securities Exchange Commission on February 25, 2025.

The foregoing description of the Board Representative Letter Agreement is not complete and is subject to and qualified in its entirety by reference to the full text of such agreement, a copy of which was included as Exhibit 4.1 to the Original Report.

Item 5.02     Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On December 3, 2025, Isabella Cunningham announced her intention to resign as a director of the Company with such resignation being effective as of the earlier of (i) the Proposed Merger Closing and (ii) the 2026 Annual Meeting.

Ms. Cunningham has served as a valuable board member of the Company since 2022. In her letter of resignation, Ms. Cunningham expressed her pleasure in serving on the Board of the Company and wished continued success to the Company after her resignation. The Company similarly appreciates her contributions during her tenure. The Company thanks Ms. Cunningham for her service to the Company and wishes her the best in her endeavors following her resignation from the board.

The Company does not anticipate reducing the size of the board upon Ms. Cunningham’s resignation but intends to keep the size of the Board the same in order to accommodate the board nominee of Castle Creek at the earlier of the Proposed Merger Closing and the 2026 Annual Meeting.

Item 8.01     Other Events.

On December 4, 2025, the Company and Castle Creek issued a joint press release announcing Castle Creek’s investment in the Company and related board representation arrangement. A copy of the press release was furnished as Exhibit 99.1 to the Original Report.

Item 9.01     Financial Statements and Exhibits.

(d) The following exhibit index lists the exhibits that are either filed or furnished with the Original Report:

EXHIBIT INDEX

Exhibit Number						Description
4.1						Form of Board Representative Letter Agreement*
99.1						Joint Press Release, dated December 4, 2025*
104						Cover Page Interactive Data File (embedded within the Inline XBRL document).
* Incorporated by reference to the exhibit of the same number in the Original Report.

SIGNATURE

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

			FIRSTSUN CAPITAL BANCORP
Date: December 10, 2025			By:			/s/ Neal E. Arnold
			Name:			Neal E. Arnold
			Title:			Chief Executive Officer

FAQ

What did FirstSun Capital Bancorp (FSUN) change in this amended 8-K/A?

The amendment corrects the signature date on a previously filed current report while leaving the underlying disclosure about the Castle Creek board representation agreement and related governance matters unchanged.

What is the board representation arrangement between FirstSun Capital Bancorp (FSUN) and Castle Creek?

FirstSun entered into a Board Representative Letter Agreement with Castle Creek Capital Partners IX, LP under which it will use its best efforts to have a Castle Creek-designated individual elected or appointed to its board and will recommend that nominee at applicable stockholder meetings.

When will Castle Creek’s board nominee join the FirstSun Capital Bancorp (FSUN) board?

The agreement provides that the Castle Creek designee’s board role begins with the earlier of the closing of FirstSun’s proposed merger with First Foundation Inc. or the company’s 2026 annual stockholders meeting.

How long do Castle Creek’s board nomination and observer rights at FirstSun Capital Bancorp (FSUN) last?

The nomination and nonvoting observer rights continue as long as Castle Creek owns at least 40% of the total shares it held on the date of the Board Representative Letter Agreement.

What did director Isabella Cunningham announce regarding her role at FirstSun Capital Bancorp (FSUN)?

On December 3, 2025, Isabella Cunningham announced her intention to resign as a director, effective at the earlier of the closing of the proposed merger with First Foundation Inc. or the 2026 annual stockholders meeting.

Will FirstSun Capital Bancorp (FSUN) change the size of its board after Isabella Cunningham’s resignation?

FirstSun does not plan to reduce the size of its board upon Ms. Cunningham’s resignation and intends to keep the size the same to accommodate Castle Creek’s board nominee.

What additional disclosure did FirstSun Capital Bancorp (FSUN) provide about Castle Creek’s investment?

FirstSun and Castle Creek issued a joint press release on December 4, 2025 announcing Castle Creek’s investment in the company and the related board representation arrangement, which was furnished as an exhibit to the original report.