Spirit of Texas Bancshares 8K Entry into a Material Definitive Agreement | STXB 25 Jul 19

Exhibit 1.1

Spirit of Texas Bancshares, Inc.

(a Texas corporation)

2,000,000 Shares of Common Stock

(No Par Value per Share)

UNDERWRITING AGREEMENT

July 25, 2019

Stephens Inc.

111 Center Street

Little Rock, Arkansas 72201

Keefe, Bruyette & Woods, Inc.

787 Seventh Avenue, 4th Floor

New York, New York 10019

as Representatives of the Underwriters

named in Schedule A hereto

Ladies and Gentlemen:

Spirit of Texas Bancshares, Inc., a Texas corporation (the “Company”), proposes, subject to the terms and conditions stated herein, to issue and sell to the several underwriters named in Schedule A hereto (each, an “Underwriter” and, collectively, the “Underwriters”), for which Stephens Inc. and Keefe, Bruyette & Woods, Inc. are acting as representatives (together, the “Representatives”), an aggregate of 2,000,000 shares (the “Firm Shares”) of common stock, no par value per share, of the Company (“Common Stock”) and, at the election of the Underwriters through the Representatives, up to an additional 300,000 shares of Common Stock (the “Option Shares” and together with the Firm Shares, the “Shares”).

The Company understands that the Underwriters propose to make a public offering of the Shares as soon as the Underwriters deem advisable after this Agreement has been executed and delivered.

The Company and the Underwriters agree that up to 95,162 Shares to be purchased by the Underwriters (the “Reserved Shares”) shall be reserved for sale by the Underwriters to certain executive officers and directors of the Company and its subsidiaries (the “Invitees”), as part of the distribution of the Shares by the Underwriters, subject to the terms of this Agreement, the applicable rules, regulations and interpretations of the Financial Industry Regulatory Authority, Inc. (“FINRA”) and all other applicable laws, rules and regulations. To the extent that such Reserved Shares are not orally confirmed for purchase by the Invitees by the end of the first business day after the date of this Agreement, such Reserved Shares may be offered to the public as part of the public offering contemplated hereby.

The Company has filed with the United States Securities and Exchange Commission (the “Commission”) a shelf registration statement onForm S-3 (FileNo. 333-232092), which includes the form of prospectus covering the registration of the Shares under the Securities Act of 1933, as amended (the “1933 Act”). Promptly after execution and delivery of this Agreement, the Company will prepare and file a prospectus supplement in accordance with the provisions of Rule 430A and/or Rule 430B of the

rules and regulations of the Commission under the 1933 Act (the “1933 Act Regulations”) and paragraph (b) of Rule 424 of the 1933 Act Regulations (“Rule 424(b)”). The information included in such prospectus supplement that was omitted from the registration statement at the time it became effective but is deemed to be part of such registration statement at the time it became effective pursuant to paragraph (b) of Rule 430A or Rule 430B of the 1933 Act Regulations is referred to as “Rule 430 Information.” Such registration statement, including any amendments thereto, the exhibits and schedules thereto, if any, but excluding FormT-1, and the documents incorporated by reference therein pursuant to Item 12 of FormS-3 under the 1933 Act, at the time it became effective, and including the Rule 430 Information, as applicable, is herein called the “Registration Statement.” Any registration statement filed pursuant to Rule 462(b) of the 1933 Act Regulations is herein referred to as a “Rule 462(b) Registration Statement” and, after such filing, the term “Registration Statement” shall include all such Rule 462(b) Registration Statements. The form of prospectus appearing in the Registration Statement at the time of its initial effectiveness and including the documents incorporated by reference therein, is hereinafter called the “Base Prospectus.” The Base Prospectus, as supplemented by the final prospectus supplement used in connection with the offering of the Shares as filed with the Commission pursuant to Rule 424(b), and including the documents incorporated by reference therein, is hereinafter called the “Prospectus.” The Base Prospectus, as supplemented by any preliminary prospectus supplement in the form of which has been or will be filed with the Commission pursuant to Rule 424(b) relating to the offering of the Shares that omits the Rule 430 Information, and including the documents incorporated by reference therein, is hereinafter called a “preliminary prospectus.” All references herein to any “preliminary prospectus” shall be deemed to mean and include, without limitation, the Statutory Prospectus (as defined below). For purposes of this Agreement, all references to the Registration Statement, the Base Prospectus, any preliminary prospectus, the Prospectus, or any amendment or supplement to any of the foregoing shall be deemed to include the copy filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval system or any successor system thereto (“EDGAR”).

All references in this Agreement to financial statements and schedules and other information which is “contained,” “included” or “stated” in the Registration Statement, the Base Prospectus, any preliminary prospectus or the Prospectus (or other references of like import) shall be deemed to mean and include all such financial statements and schedules and other information that are incorporated therein by reference; and all references in this Agreement to the terms “amend,” “amendment” or “supplement” with respect to the Registration Statement, the Base Prospectus, any preliminary prospectus or the Prospectus shall be deemed to mean and include the filing of a post-effective amendment, any document under the Securities Exchange Act of 1934, as amended (the “1934 Act”), which is incorporated therein by reference, or form of prospectus.

SECTION 1. Representations and Warranties and Agreements.

(a) Representations and Warranties of the Company. The Company represents and warrants to, and agrees with, each of the Underwriters as of the date hereof, as of the Closing Time referred to in Section 2(c) hereof, and as of each Date of Delivery (if any) referred to in Section 2(b) hereof, as follows:

(i) Compliance with Registration Requirements. (A) At the time of filing the Registration Statement, any Rule 462(b) Registration Statement and any respective post-effective amendments thereto, (B) at the earliest time thereafter that the Company or another offering participant made a bona fide offer (within the meaning of Rule 164(h)(2) of the 1933 Act Regulations) of the Shares, and (C) at the date hereof, the Company was not an “ineligible issuer” as defined in Rule 405 of the 1933 Act Regulations (“Rule 405”). The Company meets the requirements for use of FormS-3 under the 1933 Act Regulations as set forth in such form. Each of the Registration Statement and any Rule 462(b) Registration Statement has become effective under the 1933 Act and no stop order suspending the effectiveness of the Registration Statement, any Rule 462(b) Registration Statement, or any respective

post-effective amendment thereto has been issued and no proceedings for that purpose have been instituted or are pending or, to the knowledge of the Company, are contemplated by the Commission, and any request on the part of the Commission for additional information has been complied with. The Registration Statement meets the requirements set forth in Rule 415 of the 1933 Act Regulations.

At the respective times the Registration Statement, any Rule 462(b) Registration Statement and any post-effective amendments thereto became effective and at the Closing Time (and, if any Option Shares are purchased, at the Date of Delivery), the Registration Statement, any Rule 462(b) Registration Statement and any amendments and supplements thereto complied and will comply in all material respects with the requirements of the 1933 Act and the 1933 Act Regulations and did not and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. Neither the Prospectus nor any amendments or supplements thereto, at the time the Prospectus or any such amendment or supplement was issued and at the Closing Time (and, if any Option Shares are purchased, at each Date of Delivery), included or will include an untrue statement of a material fact or omitted or will omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

The Base Prospectus, each preliminary prospectus, the Prospectus and any amendments or supplements thereto, at the time each was filed or is hereafter filed with the Commission, and at the Closing Time (and, if any Option Shares are purchased, at the Date of Delivery), complied and will comply in all material respects with the 1933 Act and the 1933 Act Regulations and the Base Prospectus, any preliminary prospectus, the Prospectus and any amendments or supplements thereto delivered to the Underwriters for use in connection with this offering was and will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted byRegulation S-T.

As of the Applicable Time, neither (x) the Issuer-Represented General Free Writing Prospectus(es) (as defined below) issued at or prior to the Applicable Time and the Statutory Prospectus, all considered together (collectively, the “General Disclosure Package”), nor (y) any individual Issuer-Represented Limited Use Free Writing Prospectus (as defined below), when considered together with the General Disclosure Package, included any untrue statement of a material fact or omitted to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

The Registration Statement relating to the Shares initially became effective within three years of the date hereof. If, immediately prior to the third anniversary of the initial effective date of the Registration Statement relating to the Shares, any of the Shares remain unsold by any of the Underwriters, the Company will, prior to that third anniversary file, if it has not already done so, a new registration statement relating to the Shares, in a form reasonably satisfactory to the Representatives, will use its best efforts to cause such registration statement to be declared effective within 180 days after that third anniversary, and will take all other action necessary or appropriate to permit the public offering and sale of the Shares to continue as contemplated in the expired registration statement relating to the Shares. References herein to the Registration Statement relating to the Shares shall include such new registration statement.

As used in this subsection and elsewhere in this Agreement:

“Applicable Time” means 7:45 a.m. (Eastern time) on the date of this Agreement or such other time as agreed by the Company and the Representatives.

“Statutory Prospectus” as of any time means the Base Prospectus and the preliminary prospectus supplement relating to the offering of the Shares dated July 24, 2019, in the form first furnished to the Underwriters by the Company for use in connection with the offering of the Shares, including the documents incorporated and deemed to be incorporated by reference therein pursuant to Item 12 of FormS-3 under the 1933 Act at such time.

“Issuer-Represented Free Writing Prospectus” means any “issuer free writing prospectus,” as defined in Rule 433 of the 1933 Act Regulations (“Rule 433”), relating to the Shares that is (A) required to be filed with the Commission by the Company, (B) a “road show that is a written communication” within the meaning of Rule 433(d)(8)(i), whether or not required to be filed with the Commission, or (C) exempt from filing pursuant to Rule 433(d)(5)(i) because it contains a description of the Shares or of the offering that does not reflect the final terms, in each case in the form filed or required to be filed with the Commission or, if not required to be filed, in the form retained in the Company’s records pursuant to Rule 433(g).

“Issuer-Represented General Free Writing Prospectus” means any Issuer-Represented Free Writing Prospectus that is intended for general distribution to investors, as evidenced by its being specified in Schedule B hereto.

“Issuer-Represented Limited Use Free Writing Prospectus” means any Issuer-Represented Free Writing Prospectus that is not an Issuer-Represented General Free Writing Prospectus.

Each Issuer-Represented Free Writing Prospectus, as of its issue date and at all subsequent times through the completion of the public offering and sale of the Shares or until any earlier date that the Company notified or notifies the Representatives did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement or the Prospectus, including any document incorporated by reference therein and any preliminary prospectus or other prospectus with respect to the offering of the Shares deemed to be a part thereof that has not been superseded or modified, including any document incorporated by reference therein.

The representations and warranties in this subsection shall not apply to statements in or omissions from the Registration Statement, the Base Prospectus, any preliminary prospectus or the Prospectus or any Issuer-Represented Free Writing Prospectus made in reliance upon and in conformity with written information furnished to the Company by an Underwriter through the Representatives expressly for use therein, which the parties acknowledge and agree consists only of the information contained in the second sentence under the caption “Underwriting – Underwriting Discount,” the first sentence under the caption “Underwriting – Stabilization Transactions,” and the first sentence under the caption “Underwriting – Passive Market Making,” in each case, contained in the Registration Statement, the preliminary prospectus contained in the General Disclosure Package and the Prospectus (collectively, the “Underwriter Information”).

(ii) Incorporated Documents. The documents incorporated or deemed to be incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus, at the time they were or hereafter are filed with the Commission, complied and will comply in all material respects with the requirements of the 1934 Act and the rules and regulations of the Commission thereunder (the “1934 Act Regulations”), and, when read together with the other information in the Registration Statement, the General Disclosure Package, and the Prospectus, at the time the Registration Statement became effective or when such incorporated documents were filed with the Commission, as the case may be, did not and at the Applicable Time did not and at the Closing Time will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading.

(iii) Independent Accountants. Each of (A) BDO USA, LLP (“BDO”), the accounting firm that certified the financial statements of the Company included in the Registration Statement, the General Disclosure Package and the Prospectus, and (B) BKD, LLP (“BKD”), the accounting firm that certified the financial statements of First Beeville Financial Corporation (“Beeville”) included in the Registration Statement, the General Disclosure Package and the Prospectus, is an independent registered public accounting firm as required by the 1933 Act and the 1933 Act Regulations. With respect to the Company, neither BDO nor, to the knowledge of the Company, BKD is or has been in violation of the auditor independence requirements of the Sarbanes-Oxley Act of 2002 (“Sarbanes-Oxley Act”) and the related rules and regulations of the Commission.

(iv) Financial Statements. The financial statements incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus present fairly, in all material respects, (A) the financial position of (1) the Company and its consolidated subsidiaries, (2) to the knowledge of the Company, Beeville and its consolidated subsidiaries, (3) to the knowledge of the Company, Comanche National Corporation (“Comanche”) and its consolidated subsidiaries, and (4) to the knowledge of the Company, Chandler Bancorp, Inc. (“Chandler”) and its consolidated subsidiaries at the dates indicated and (B) the consolidated statements of income and comprehensive income, changes in stockholders’ equity, and cash flows of (1) the Company and its consolidated subsidiaries, (2) to the knowledge of the Company, Beeville and its consolidated subsidiaries, (3) to the knowledge of the Company, Comanche and its consolidated subsidiaries, and (4) to the knowledge of the Company, Chandler and its consolidated subsidiaries, for the periods specified; said financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) applied on a consistent basis throughout the periods involved. The pro forma financial statements incorporated by reference in, and the pro forma information included in, the Registration Statement, the General Disclosure Package and the Prospectus, together with the notes related thereto (A) present fairly, in all material respects, the financial position of (1) the Company and its consolidated subsidiaries, and (2) to the knowledge of the Company, Beeville, Comanche and Chandler and their respective consolidated subsidiaries, at the dates and for the periods specified on a combined pro forma basis as of the date specified, and (B) present fairly, in all material respects, the results of operations of (1) the Company and its consolidated subsidiaries and (2) to the knowledge of the Company, Beeville, Comanche and Chandlerand their respective consolidated subsidiaries for the periods specified on a combined pro forma basis; said pro forma financial statements and pro forma information referred to in (A) and (B) have been prepared in conformity with the requirements of Article 11 of RegulationS-X under the 1933 Act and GAAP, applied on a consistent basis throughout the periods involved, and give effect to assumptions and adjustments made in good faith and on a reasonable basis as set forth therein. The supporting schedules, if any, included in the Registration Statement, the General Disclosure Package and the Prospectus present fairly, in all material respects, in accordance with GAAP the information required to be stated therein. The selected financial data and the summary financial information included in the Registration Statement, the General Disclosure Package and the Prospectus present fairly, in all material respects, the information shown therein and have been compiled on a basis consistent with that of the audited financial statements incorporated by reference in the Registration Statement and the books and records of the Company. No other financial statements (including any pro forma financial statements) or schedules are required to be included in the Registration Statement. To the extent applicable, all disclosures contained in the Registration Statement, the General Disclosure Package or the Prospectus regarding“non-GAAP financial measures” (as such term is defined by the rules and regulations of the Commission) comply with Regulation G of the 1934 Act, the 1934 Act Regulations and Item 10(e) of RegulationS-K under the 1933 Act, as applicable. The Company is subject to the reporting requirements of the 1934 Act and, during the last 12 months, has timely filed all reports required thereby. The interactive data in eXtensible Business Reporting Language incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus is updated as necessary to comply, in all material respects, with the requirements of the 1933 Act and the Commission’s rules and guidelines applicable thereto and present fairly, in all

material respects, the consolidated financial position, results of operations and changes in financial position of the Company and its subsidiaries on the basis stated in the Registration Statement at the respective dates or for the respective periods to which they apply.

(v) No Material Adverse Change in Business. Since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package and the Prospectus, (A) no event or events have occurred that, individually or in the aggregate, has had or would reasonably be expected to have a Material Adverse Effect (as defined below), (B) the Company and its subsidiaries have conducted their respective businesses in all material respects in the ordinary course, consistent with prior practice, and there have been no transactions entered into by the Company or any of its subsidiaries or, to the knowledge of the Company, Chandler or any of its subsidiaries, other than those in the ordinary course of business and the transactions contemplated by the Agreement and Plan of Reorganization, dated as of July 24, 2019, by and between the Company and Chandler, and joined in by Kidd Partners, Ltd. as the sole shareholder of Chandler (the “Merger Agreement”), which are material with respect to each of the Company and its subsidiaries or Chandler and its subsidiaries, each considered as a separate consolidated enterprise, (C) there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its capital stock and, to the Company’s knowledge, there has not been any dividend or distribution of any kind declared, paid or made by Chandler on any class of its capital stock, (D) neither the Company nor any of its subsidiaries has incurred any liabilities, direct or contingent, including without limitation any losses or interference with its business from fire, explosion, flood, earthquake, accident or other calamity, whether or not covered by insurance, or from any strike, labor dispute or court or governmental action, order or decree, that would have a Material Adverse Effect, or has entered into any transactions not in the ordinary course of business that are material to the Company and its subsidiaries taken as a whole and (E) there has not been any material decrease in the capital stock or any material increase in any short-term or long-term indebtedness of the Company or its subsidiaries. For purposes of this Agreement, “Material Adverse Effect” means any fact, change, occurrence, event or circumstance that, individually or together with any other facts, changes, occurrences, events or circumstances, has or would reasonably be expected to have a material adverse effect on the business, business prospects, management, financial position, shareholders’ equity or results of operations of the Company and its subsidiaries, considered as one enterprise, or would prevent or impair the consummation of the transactions contemplated by this Agreement. As used in this paragraph, references to the Registration Statement, the General Disclosure Package and the Prospectus exclude any amendments or supplements thereto subsequent to the date of this Agreement.

(vi) Good Standing of the Company. The Company has been duly organized and is validly existing as a corporation in good standing under the laws of the State of Texas and has corporate power and authority to own, lease and operate its properties and to conduct its business as described in the General Disclosure Package and the Prospectus and to enter into and perform its obligations under this Agreement; and the Company is duly qualified as a foreign corporation to transact business and is in good standing in each other jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure so to qualify or to be in good standing would not reasonably be expected to result in a Material Adverse Effect.

(vii) Good Standing of Subsidiaries; Chandler. Each significant subsidiary (as defined in paragraph (w) of Rule1-02 of RegulationS-X) of the Company (each, a “Significant Subsidiary”) and, to the knowledge of the Company, Chandler and each of its Significant Subsidiaries has been duly organized and is validly existing as a banking association, corporation, business trust, partnership or limited liability company in good standing under the laws of the jurisdiction of its incorporation, formation or organization, has the requisite power and authority to own, lease and operate its properties and to conduct its business as described in the General Disclosure Package and the

Prospectus and is duly qualified as a foreign corporation or other business entity to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure so to qualify or to be in good standing would not reasonably be expected to result in a Material Adverse Effect. All of the issued and outstanding capital stock of each such Significant Subsidiary has been duly authorized and validly issued, is fully paid andnon-assessable and, except as disclosed in the Registration Statement, General Disclosure Package and Prospectus, is owned by the Company, directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance, claim or equity; none of the outstanding shares of capital stock of any subsidiary was issued in violation of the preemptive or similar rights of any securityholder of such subsidiary. Spirit of Texas Bank, SSB, a Texas state savings bank (the “Bank”), is the only Significant Subsidiary of the Company and is the only depositary institution subsidiary of the Company. Citizens State Bank, a Texas state chartered bank (“Citizens Bank”), is the only Significant Subsidiary (as defined in paragraph (w) of Rule1-02 of RegulationS-X) of Chandler. A list of all subsidiaries of each of the Company and Chandler is contained on ScheduleD-1 hereto.

(viii) Capitalization. The authorized, issued and outstanding capital stock of the Company is as set forth in the General Disclosure Package and the Prospectus in the column entitled “Actual” under the caption “Capitalization” (except for subsequent issuances, if any, pursuant to this Agreement, the Merger Agreement, pursuant to reservations, agreements or employee benefit plans referred to in the Prospectus or pursuant to the exercise of convertible securities, warrants or options referred to in the Prospectus, including in the information incorporated therein by reference). All shares of the issued and outstanding capital stock of each of the Company and, to the knowledge of the Company, Chandler have been duly authorized and validly issued and are fully paid andnon-assessable; none of the outstanding shares of capital stock was issued in violation of the preemptive or other similar rights of any securityholder of the Company or Chandler.

(ix) Authorization of Agreement. This Agreement has been duly authorized, executed and delivered by the Company.

(x) Securities Offerings. Since the Company became subject to the reporting requirements of the 1934 Act, all offers and sales of the Company’s capital stock and debt or other securities prior to the date hereof were made in compliance with or were the subject of an available exemption from the 1933 Act and the 1933 Act Regulations and all other applicable state and federal laws or regulations, or any actions under the 1933 Act and the 1933 Act Regulations or any state or federal laws or regulations in respect of any such offers or sales are effectively barred by effective waivers or statutes of limitation.

(xi) Authorization and Description of Shares. The Shares to be purchased by the Underwriters from the Company have been duly authorized for issuance and sale to the Underwriters pursuant to this Agreement and, when issued and delivered by the Company pursuant to this Agreement against payment of the consideration set forth herein, will be validly issued and fully paid andnon-assessable; the Common Stock conforms to all statements relating thereto contained in the Prospectus and such description conforms to the rights set forth in the instruments defining the same; no holder of the Shares will be subject to personal liability for the debts of the Company by reason of being such a holder; and the issuance of the Shares is not subject to the preemptive or other similar rights of any securityholder of the Company other than those rights which have been validly waived by the securityholder entitled to such rights prior to the date of this Agreement.

(xii) Summaries of Legal Matters. The statements set forth in the Registration Statement, the General Disclosure Package and the Prospectus under the captions “Description of Common Stock” and “Legal Matters” and under the captions “Supervision and Regulation” and “Legal

Proceedings” in the Company’s Annual Report on Form10-K for the year ended December 31, 2018, insofar as they purport to describe legal matters or provisions of the laws and regulations or documents referred to therein, are accurate, reasonably complete and reasonably fair; and the statements set forth in the General Disclosure Package and the Prospectus under the caption “Material U.S. Federal Income Tax Consequences toNon-U.S.”, insofar as they purport to summarize certain federal income tax laws of the United States, constitute a reasonably fair summary of the principal U.S. federal income tax consequences of an investment in the Shares.

(xiii) Absence of Defaults and Conflicts. Neither the Company nor any of its subsidiaries nor, to the Company’s knowledge, Chandler, is (A) in violation of its charter or bylaws (or other organization documents) or (B) in default in the performance or observance of any obligation, agreement, covenant or condition contained in any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or other agreement or instrument to which the Company, any of its subsidiaries or Chandler or Citizens Bank is a party or by which it or any of them may be bound, or to which any of the property or assets of the Company, any of its subsidiaries or Chandler or Citizens Bank is subject (collectively, “Agreements and Instruments”) except for such defaults that would not reasonably be expected to result in a Material Adverse Effect; and the execution, delivery and performance of this Agreement and the consummation of the transactions contemplated herein and in the General Disclosure Package (including the issuance and sale of the Shares and the use of the proceeds from the sale of the Shares as described in the Prospectus under the caption “Use of Proceeds”) and compliance by the Company with its obligations hereunder have been duly authorized by all necessary corporate action and do not and will not, whether with or without the giving of notice or passage of time or both, conflict with or constitute a breach of, or default or Repayment Event (as defined below) under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company, any of its subsidiaries or, to the Company’s knowledge, Chandler or Citizens Bank pursuant to, the Agreements and Instruments (except for such conflicts, breaches or defaults or liens, charges or encumbrances that would not reasonably be expected to result in a Material Adverse Effect), nor will such action result in any violation of the provisions of the charter or bylaws (or other organization documents) of the Company, any of its subsidiaries or, to the Company’s knowledge, Chandler or Citizens Bank or any applicable law, statute, rule, regulation, judgment, order, writ or decree of any government, government instrumentality or court, domestic or foreign, having jurisdiction over the Company, any of its subsidiaries or Chandler or Citizens Bank or any of their assets, properties or operations. As used herein, a “Repayment Event” means any event or condition which gives the holder of any note, debenture or other evidence of indebtedness (or any person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or any portion of such indebtedness by the Company, any of its subsidiaries or, to the Company’s knowledge, Chandler or Citizens Bank. All consents, approvals, licenses, qualifications, authorizations or other orders of any court, regulatory body, administrative agency or other governmental agency or body that are required for the execution and delivery of this Agreement or the consummation of the transactions contemplated by this Agreement, including the issuance, sale, authentication and delivery of the Shares, have been obtained, except such consents, approvals authorizations, registrations or qualifications as may be required under the rules of Nasdaq (as defined below) or under state securities or Blue Sky laws in connection with the purchase and distribution of the Shares by the Underwriters.

(xiv) Nasdaq Compliance. The Company is in compliance in all material respects with the requirements of The Nasdaq Global Select Market (“Nasdaq”) for continued listing of its Common Stock thereon. The Company has taken no action designed to, or likely to have the effect of, terminating the registration of the Common Stock under the 1934 Act or the listing of its Common Stock on Nasdaq, nor has the Company received any notification that the Commission or Nasdaq is contemplating terminating such registration or listing. The transactions contemplated by this Agreement will not contravene the rules and regulations of Nasdaq.

(xv) Absence of Labor Dispute. No labor dispute with the employees of the Company or any subsidiary exists or, to the knowledge of the Company, is imminent, which would reasonably be expected to result in a Material Adverse Effect.

(xvi) Absence of Proceedings. There is no action, suit, proceeding, inquiry or investigation before or brought by any court or governmental agency or body, domestic or foreign, now pending, or, to the knowledge of the Company, threatened, against or affecting the Company, any subsidiary or, to the knowledge of the Company, Chandler, which is required to be disclosed in the Registration Statement (other than as disclosed therein), or which would reasonably be expected to result in a Material Adverse Effect; the aggregate of all pending legal or governmental proceedings to which the Company, any subsidiary or Chandler is a party or of which any of their respective property or assets is the subject which are not described in the Registration Statement, including ordinary routine litigation incidental to the business, could not reasonably be expected to result in a Material Adverse Effect.

(xvii) Material Contracts. The material contracts to which the Company or any of its subsidiaries is a party, have been duly and validly authorized, executed and delivered by the Company or its subsidiaries, as the case may be, and constitute the legal, valid and binding agreements of the Company or its subsidiaries, enforceable by and against the Company or each of its subsidiaries that is a party thereto in accordance with their respective terms, except as such enforceability may be limited by applicable bankruptcy, insolvency, reorganization or other similar laws relating to enforcement of creditors’ rights generally, and general equitable principles relating to the availability of remedies, and subject to 12 U.S.C. § 1818(b)(6)(D) (or any successor statute) and similar bank regulatory powers and to the application of principles of public policy, and except as rights to indemnity or contribution may be limited by federal or state securities laws and the public policy underlying such laws.

(xviii) Bank Holding Company Act. The Company and Chandler have each been duly registered as a bank holding company under the applicable provisions of the Bank Holding Company Act of 1956, as amended. Each of the Company and the Bank is in compliance in all material respects with all applicable laws administered by and regulations of the Board of Governors of the Federal Reserve System, the Federal Deposit Insurance Corporation (the “FDIC”), and the Texas Department of Savings and Mortgage Lending, as applicable (collectively, the “Bank Regulatory Authorities”). None of the Company or its subsidiaries is subject or is party to, or has received any notice or advice that any of them may become subject or party to any investigation with respect to, any corrective, suspension orcease-and-desist order, agreement, consent agreement, memorandum of understanding or other regulatory enforcement action, proceeding or order with or by, or is a party to any commitment letter or similar undertaking to, or is subject to any directive by, or has been a recipient of any supervisory letter (including, without limitation, any notification from the Federal Reserve of a proposal to increase the minimum capital requirements of the Company or any of its subsidiaries, pursuant to the Federal Reserve’s authority under 12 U.S.C. 3907(a)(2)) from, or has adopted any board resolutions at the request of, any governmental or regulatory agency that currently relates to or restricts in any material respect the conduct of their business or that in any manner relates to their capital adequacy, credit policies or management (each, a “Regulatory Agreement”), nor has the Company or any of its subsidiaries been advised by any governmental or regulatory agency that it is considering issuing or requesting any such Regulatory Agreement. The Bank and Citizens Bank are each an insured depository institution and each has received a Community Reinvestment Act rating of “Satisfactory” or better. There is no unresolved violation, criticism or exception by any governmental or regulatory agency with respect to any report or statement relating to any examinations of the Company or any of its subsidiaries which is reasonably likely to result in a Material Adverse Effect.

(xix) No Restrictions; No Transactions. No subsidiary of the Company is currently prohibited, directly or indirectly, under any order, agreement or other instrument of the Federal Reserve or the Texas Department of Savings and Mortgage Lending (other than orders, agreements or instruments applicable to banks and their holding companies and their subsidiaries generally), or any other federal or state bank regulatory authorities with jurisdiction over the Company or any of its subsidiaries, under any applicable law, or under any agreement or other instrument to which it is a party or is subject, from paying any dividends to the Company, from making any other distribution on such subsidiary’s capital stock, from repaying to the Company any loans or advances to such subsidiary from the Company or from transferring any of such subsidiary’s properties or assets to the Company or any other subsidiary of the Company. The deposit accounts of the Bank are insured by the Deposit Insurance Fund to the fullest extent permitted by the law and the rules and regulations of the FDIC and no proceeding for the revocation or termination of such deposit insurance has been instituted or is pending or, to the knowledge of the Company, is threatened. Neither the Company nor any of its subsidiaries is a party to a letter of intent, accepted term sheet or similar instrument or any binding agreement that contemplates an acquisition, disposition, transfer or sale of the assets (as a going concern) or capital stock of the Company or of any subsidiary or business unit or any similar business combination transaction which would be material to the Company and its subsidiaries taken as a whole.

(xx) Accuracy of Exhibits. There are no contracts or documents which are required to be described in the Registration Statement, the General Disclosure Package, the Prospectus or the documents incorporated by reference therein or required to be filed as exhibits thereto which have not been so properly described and filed as required.

(xxi) Possession of Intellectual Property. The Company and its subsidiaries own or possess, or can acquire on reasonable terms, adequate patents, patent rights, licenses, inventions, copyrights,know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures and excluding generally commercially available “off the shelf” software programs licensed pursuant to shrink wrap or “click and accept” licenses), trademarks, service marks, trade names or other intellectual property (collectively, “Intellectual Property”) necessary to carry on the business now operated by them. Neither the Company nor any of its subsidiaries has received any notice or has knowledge of any infringement or misappropriation of or conflict with asserted rights of others with respect to any Intellectual Property or of any facts or circumstances which would render any Intellectual Property invalid or inadequate to protect the interest of the Company or any of its subsidiaries therein, and which infringement, misappropriation or conflict (if the subject of any unfavorable decision, ruling or finding) or invalidity or inadequacy, individually or in the aggregate, would reasonably be expected to result in a Material Adverse Effect.

(xxii) Absence of Further Requirements. No filing with, or authorization, approval, consent, license, order, registration, qualification or decree of, any court or governmental authority or agency is necessary or required for the performance by the Company of its obligations hereunder, in connection with the offering, issuance or sale of the Shares hereunder or the consummation of the transactions contemplated by this Agreement, except such as have been already obtained or as may be required under the 1933 Act or the 1933 Act Regulations, the rules of Nasdaq, the securities laws of any state ornon-U.S. jurisdiction or the rules of FINRA. All of the information provided to the Underwriters or to counsel for the Underwriters by the Company, its counsel, its officers and directors and the holders of any securities (debt or equity) or options to acquire any securities of the Company in connection with the offering of the Shares is true, complete, correct and compliant with FINRA’s rules, in all material respects, and any letters, filings or other supplemental information provided to FINRA pursuant to FINRA Rules or National Association of Securities Dealers Conduct Rules are true, complete and correct in all material respects.

(xxiii) Possession of Licenses and Permits. The Company and its subsidiaries possess such permits, licenses, approvals, consents and other authorizations (collectively, “Governmental Licenses”) issued by the appropriate federal, state, local or foreign regulatory agencies or bodies necessary to conduct the business now operated by them, except where the failure to so possess such a Governmental License would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; the Company and its subsidiaries are in compliance with the terms and conditions of all Governmental Licenses, except where the failure so to comply would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; all of the Governmental Licenses are valid and in full force and effect, except where the invalidity of such Governmental Licenses or the failure of such Governmental Licenses to be in full force and effect would not reasonably be expected to have a Material Adverse Effect; and neither the Company nor any of its subsidiaries has received any notice of proceedings relating to the revocation or modification of any such Governmental Licenses which, individually or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would reasonably be expected to result in a Material Adverse Effect. Neither the Company nor any of its subsidiaries has failed to file with applicable regulatory authorities any statement, report, information or form required by any applicable law, regulation or order, except where the failure to be so in compliance would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect, all such filings were in material compliance with applicable laws when filed and no material deficiencies have been asserted by any regulatory commission, agency or authority with respect to any such filings or submissions.

(xxiv) Title to Property. The Company and its subsidiaries have good and marketable title to all real property owned by the Company and its subsidiaries and good title to all other properties owned by them, in each case, free and clear of all mortgages, pledges, liens, security interests, claims, restrictions or encumbrances of any kind except such as do not, individually or in the aggregate, materially affect the value of such property and do not interfere with the use made and proposed to be made of such property by the Company or any of its subsidiaries; and all of the leases and subleases material to the business of the Company and its subsidiaries, considered as one enterprise, and under which the Company or any of its subsidiaries holds properties described in the General Disclosure Package and the Prospectus, are in full force and effect, and neither the Company nor any subsidiary of the Company has any notice of any material claim of any sort that has been asserted by anyone adverse to the rights of the Company or any subsidiary of the Company under any of the leases or subleases mentioned above, or affecting or questioning the rights of the Company or such subsidiary of the Company to the continued possession of the leased or subleased premises under any such lease or sublease.

(xxv) Investment Company Act. The Company is not, and upon the issuance and sale of the Shares as herein contemplated and the application of the net proceeds therefrom as described in the General Disclosure Package and the Prospectus will not be, an “investment company” or an entity “controlled” by an “investment company” as such terms are defined in the Investment Company Act of 1940, as amended.

(xxvi) Environmental Laws. Except as would not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Effect, (A) neither the Company nor any of its subsidiaries is in violation of any federal, state, local or foreign statute, law, rule, regulation, ordinance, code, policy or rule of common law or any judicial or administrative interpretation thereof, including any judicial or administrative order, consent, decree or judgment, relating to pollution or protection of human health, the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata) or wildlife, including, without limitation, laws and regulations relating to the release or threatened release of chemicals, pollutants, contaminants, wastes, toxic substances, hazardous substances, petroleum or petroleum products, asbestos-containing materials or mold (collectively,

“Hazardous Materials”) or to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Hazardous Materials (collectively, “Environmental Laws”), (B) the Company and its subsidiaries have all permits, authorizations and approvals required under any applicable Environmental Laws and are each in compliance with the requirements of such permits, authorizations and approvals, (C) there are no pending or, to the knowledge of the Company, threatened administrative, regulatory or judicial actions, suits, demands, demand letters, claims, liens, notices of noncompliance or violation, investigation or proceedings relating to any Environmental Law against the Company or any of its subsidiaries, (D) there are no events or circumstances that might reasonably be expected to form the basis of an order forclean-up or remediation, or an action, suit or proceeding by any private party or governmental body or agency, against or affecting the Company or any of its subsidiaries relating to Hazardous Materials or any Environmental Laws and (E) none of the Company or any of its subsidiaries anticipate material capital expenditures relating to Environmental Laws.

(xxvii) Taxes. The Company and each of its subsidiaries has (A) timely filed all material foreign, federal, state and local tax returns, information returns, and similar reports that are required to be filed (taking into account valid extensions), and all such returns and reports are true, correct and complete in all material respects, (B) paid in full all taxes required to be paid by it and any other assessment, fine or penalty levied against it, except for any such tax assessment, fine or penalty that is currently being contested in good faith or as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect, and (C) established on the Company’s most recent consolidated balance sheet reserves that are adequate for the payment of all taxes not yet due and payable.

(xxviii) Insurance. The Company and its subsidiaries carry, or are covered by, insurance in such amounts and covering such risks as the Company reasonably believes are adequate for the conduct of the business of the Company and its subsidiaries and the value of their properties and as are customary in the business in which the Company and its subsidiaries are engaged; neither the Company nor any of its subsidiaries has been refused any insurance coverage sought or applied for; and the Company has no reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not reasonably be expected to have a Material Adverse Effect.

(xxix) Statistical and Market Data. The statistical and market-related data contained in the Registration Statement, the General Disclosure Package and the Prospectus comply in all material respects with the requirements of Commission Industry Guide 3 (where applicable) and are based on or derived from sources which the Company believes are reliable and accurate, and the Company has obtained the written consent to the use of such data from such sources to the extent required.

(xxx) Relationship. No relationship, direct or indirect, exists between or among the Company or any of its subsidiaries, on the one hand, and the directors, officers, shareholders, customers or suppliers of the Company or any of its subsidiaries, on the other, that is required by the 1933 Act or by the 1933 Act Regulations to be described in the Registration Statement and/or the Prospectus and that is not so described.

(xxxi) Lending Relationship. The Company (A) does not have any material lending or other relationship with any banking or lending affiliate of any Underwriter and (B) does not intend to use any of the proceeds from the sale of the Shares to repay any outstanding debt owed to any affiliate of any Underwriter.

(xxxii) Internal Control Over Financial Reporting. The Company and its subsidiaries maintain a system of internal control over financial reporting (as defined in Rule13a-15(f) under the 1934 Act) that complies with the requirements of the 1934 Act and has been designed by or is under the

supervision of the Company’s principal executive officer and principal financial officer, or persons performing similar functions, and provides reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles, including that (A) transactions are executed in accordance with management’s general or specific authorizations; (B) transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and to maintain asset accountability; (C) access to assets of the Company and its subsidiaries is permitted only in accordance with management’s general or specific authorization; (D) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences; and (E) the interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement is accurate and fairly presents the information called for in all material respects and has been prepared in accordance with the Commission’s rules and guidelines applicable thereto. The systems of internal control over financial reporting of the Company and its subsidiaries are overseen by the Audit Committee of the Board of Directors of the Company in accordance with Nasdaq rules and regulations. Since the end of the Company’s most recent audited fiscal year, there has been (i) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (ii) no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

(xxxiii) Disclosure Controls and Procedures. The Company and its subsidiaries maintain a system of disclosure controls and procedures (as such term is defined in Rule13a-15(e) under the 1934 Act), which (A) are designed to ensure that information required to be disclosed by the Company in the reports that it files or submits under the 1934 Act is recorded, processed, summarized and reported within the time periods specified in the Commission’s rules and forms and that material information relating to the Company and its subsidiaries is made known to the Company’s principal executive officer and principal financial officer by others within the Company and its subsidiaries to allow timely decisions regarding disclosure, and (B) are effective in all material respects to perform the functions for which they were established. Based on the evaluation of the Company’s and its subsidiaries disclosure controls and procedures described above, the Company is not aware of (1) any significant deficiency in the design or operation of internal controls which could materially adversely affect the Company’s ability to record, process, summarize and report financial data or any material weakness in internal controls or (2) any fraud, whether or not material, that involves management or other employees who have a significant role in the Company’s internal controls. Since the most recent evaluation of the Company’s disclosure controls and procedures described above, there have been no significant changes in internal controls or in other factors that could significantly affect internal controls.

(xxxiv) Compliance with the Sarbanes-Oxley Act. There is and has been no failure on the part of the Company or any of the Company’s directors or officers, in their capacities as such, to comply in all material respects with any provision of the Sarbanes-Oxley Act and the rules and regulations promulgated in connection therewith, including Section 402 related to loans and Sections 302 and 906 related to certifications.

(xxxv) Pending Procedures and Examinations. The Registration Statement is not the subject of a pending proceeding or examination under Section 8(d) or 8(e) of the 1933 Act, and the Company is not the subject of a pending proceeding under Section 8A of the 1933 Act in connection with the offering of the Shares.

(xxxvi) Unlawful Payments. Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company, Chandler nor any of its subsidiaries nor any director, officer, agent, employee or other person associated with or acting on behalf of the Company, Chandler or any of their respective subsidiaries, any of the respective affiliates of the Company, Chandler or any of their respective subsidiaries or any other person associated with or acting on behalf of the Company, Chandler or any of their

respective subsidiaries or their respective affiliates has (A) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity, (B) made any direct or indirect unlawful payment or giving of money, property, gifts or anything else of value, directly or indirectly, to any foreign or domestic government official (including any officer or employee of a government or government-owned or controlled entity or of a public international organization, or any person acting in an official capacity for or on behalf of any of the foregoing, or any political party or party official or candidate for public office) from corporate funds, (C) violated or is in violation of any provision of the Foreign Corrupt Practices Act of 1977, as amended (the “FCPA”), or any applicable law or regulations implementing the OECD Convention on Combating Bribery of Foreign Public Officials in International Business Transactions, or committed an offense under the Bribery Act 2010 of the United Kingdom, or any applicable anti-bribery or anti-corruption statute or regulation or (D) made any bribe, rebate, payoff, influence payment, kickback or other payment or benefit in violation of any applicable law, rule or regulation. The Company and its subsidiaries and their respective affiliates and, to the knowledge of the Company, Chandler and its subsidiaries and their respective affiliates, have conducted their businesses in compliance with the FCPA and all other applicable anti-bribery and anti-corruption laws and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith.

(xxxvii) Anti-Money Laundering Laws. Neither the Company nor any of its subsidiaries, has violated or is in violation of the Currency and Foreign Transactions Reporting Act of 1970, as amended, and the applicable anti-money laundering statutes of all jurisdictions where the Company and its subsidiaries and affiliates conduct business, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Money Laundering Laws is pending or, to the best knowledge of the Company, threatened.

(xxxviii) OFAC. None of the Company, any subsidiary of the Company or, to the knowledge of the Company or any director, officer, agent, employee, affiliate or other person acting on behalf of the Company or any of its subsidiaries is (A) engaged in any services (including financial services), transfers of goods, software, or technology, or any other business activity related to (1) Cuba, Iran, North Korea, Sudan, Syria, the Crimea region of Ukraine claimed by Russia or any other country or territory that is, or whose government is, the subject of sanctions that broadly prohibit dealings with that country or territory (collectively, the “Sanctioned Countries” and each, a “Sanctioned Country”), (2) the government of any Sanctioned Country, (3) any person, entity or organization located in, resident in, formed under the laws of, or owned or controlled by the government of, any Sanctioned Country, or (4) any person, entity or organization made subject of any sanctions administered or enforced by the United States Government, including, without limitation, the list of Specially Designated Nationals (“SDN List”) of the United States Department of the Treasury’s Office of Foreign Assets Control (“OFAC”), or by the United Nations Security Council, the European Union, Her Majesty’s Treasury, or other relevant sanctions authority (collectively, “Sanctions”), (B) engaged in any transfers of goods, technologies or services (including financial services) that may assist the governments of Sanctioned Countries or facilitate money laundering or other activities proscribed by United States Law, or (C) is a person, entity or organization currently the subject of any Sanctions or (D) located, organized or resident in any Sanctioned Country;

(xxxix) No Registration Rights. Except as disclosed in the General Disclosure Package and the Prospectus, no person has the right to require the Company or any of its subsidiaries to register any securities for sale under the 1933 Act by reason of the filing of the Registration Statement with the Commission or the issuance and sale of the Shares to be sold by the Company hereunder.

(xl) No Stabilization or Manipulation. Neither the Company nor any of its subsidiaries, nor any affiliates of the Company or its subsidiaries, has taken, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization or manipulation of the price of the Shares or to result in a violation of Regulation M under the 1934 Act.

(xli) No Unauthorized Use of Prospectus. The Company has not distributed and, prior to the later to occur of (A) the Closing Time and (B) completion of the distribution of the Shares, will not distribute any prospectus (as such term is defined in the 1933 Act and the 1933 Act Regulations) in connection with the offering and sale of the Shares other than the Registration Statement, the Base Prospectus, any preliminary prospectus, the Statutory Prospectus or the Prospectus or other materials, if any, permitted by the 1933 Act or by the 1933 Act Regulations and approved by the Representatives.

(xlii) No Unlawful Offering of Reserved Shares. The Company has not offered, or caused the Underwriters to offer, Reserved Shares to any Invitee or any other person with the specific intent to unlawfully influence (A) a customer or vendor of the Company to alter the customer’s or vendor’s level or type of business with the Company, or (B) a trade journalist or publication to write or publish favorable information about the Company or its products or services.

(xliii) Forward-Looking Statements. No forward-looking statement (within the meaning of Section 27A of the 1933 Act and Section 21E of the 1934 Act) contained in the Registration Statement and the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith.

(xliv) Lock-up Agreements. Each of the Company’s officers, as defined by Rule16a-1(f) of the 1934 Act Regulations, and directors, in each case as listed on Schedule E hereto, has executed and delivered alock-up agreement as contemplated by Section 5(j) hereof.

(xlv) No Fees or Advisory Rights. Other than as contemplated by this Agreement, there is no broker, finder or other party that is entitled to receive from the Company or any subsidiary any brokerage or finder’s fee or any other fee, commission or payment as a result of the transactions contemplated by this Agreement. No person has the right to act as a financial advisor to the Company in connection with the offer and sale of the Shares.

(xlvi) ERISA. The Company and each of its subsidiaries or their “ERISA Affiliates” (as defined below) are in compliance in all material respects with all presently applicable provisions of the Employee Retirement Income Security Act of 1974, as amended, including the regulations and published interpretations thereunder (collectively, “ERISA”); no “reportable event” (as defined in ERISA) has occurred with respect to any “employee benefit plan” (as defined in ERISA) for which the Company or any of its subsidiaries or ERISA Affiliates would have any material liability; the Company and each of its subsidiaries or their ERISA Affiliates have not incurred and do not expect to incur liability under (A) Title IV of ERISA with respect to termination of, or withdrawal from, any “employee benefit plan” or (B) Sections 412, 4971, 4975 or 4980B of the United States Internal Revenue Code of 1986, as amended, and the regulations and published interpretations thereunder (collectively the “Code”); and each “employee benefit plan” for which the Company and each of its subsidiaries or any of their ERISA Affiliates would have any liability that is intended to be qualified under Section 401(a) of the Code is so qualified in all material respects and nothing as occurred, whether by action or by failure to act, which would cause the loss of such qualification. “ERISA Affiliate” means, with respect to the Company or a subsidiary, any member of any group of organizations described in Sections 414(b), (c), (m) or (o) of the Code or Section 400(b) of ERISA of which the Company or such subsidiary is a member.

(xlvii) Derivative Instruments. Any and all material swaps, caps, floors, futures, forward contracts, option agreements (other than stock options issued to the Company’s employees, directors, agents or consultants) and other derivative financial instruments, contracts or arrangements, whether entered into for the account of the Company or one of its subsidiaries or for the account of a customer of the Company or one of its subsidiaries, were entered into in the ordinary course of business and in accordance, in all material respects, with applicable laws, rules, regulations and policies of all applicable regulatory agencies and with counterparties believed by the Company to be financially responsible at the time. The Company and each of its subsidiaries have duly performed in all material respects all of their obligations thereunder to the extent that such obligations to perform have accrued, and there are no breaches, violations or defaults or allegations or assertions of such by any party thereunder which would, individually or in the aggregate, reasonably be expected to result in a Material Adverse Effect.

(xlviii) Off-Balance Sheet Transactions. There is no transaction, arrangement or other relationship between the Company or any of its subsidiaries and an unconsolidated or otheroff-balance sheet entity that is required to be disclosed by the Company in its 1934 Act filings and is not so disclosed or that otherwise would be reasonably expected to have a Material Adverse Effect.

(xlix) Emerging Growth Company Status. From the time of the initial filing of the Registration Statement with the Commission through the date hereof, the Company has been and is an “emerging growth company,” as defined in Section 2(a) of the 1933 Act (an “Emerging Growth Company”).

(l) Termination of Contracts. Except as would not have a Material Adverse Effect, neither the Company nor the Bank has sent or received any communication regarding termination of, or intent not to renew, any of the contracts or agreements referred to or described in the General Disclosure Package and the Prospectus, or referred to or described in, or filed as an exhibit to, the General Disclosure Package and the Prospectus, and no such termination ornon-renewal has been threatened by the Company or the Bank or, to the Company’s knowledge, any other party to any such contract or agreement.

(li) Margin Rules. The application of the proceeds received by the Company from the issuance, sale and delivery of the Shares as described in the Registration Statement, the General Disclosure Package and the Prospectus will not violate Regulation T, U or X of the Federal Reserve or any other regulation of the Federal Reserve.

(lii) Cybersecurity. (A) There has been no security breach or incident, unauthorized access or disclosure, or other compromise of or relating to any of the Company’s or its subsidiaries’ information technology and computer systems, networks, hardware, software, data and databases (including the data and information of their respective customers, employees, suppliers, vendors and any third party data maintained, processed or stored by the Company and its subsidiaries, and, to the knowledge of the Company, any such data processed or stored by third parties on behalf of the Company and its subsidiaries, equipment or technology) (collectively, “IT Systems and Data”) that would, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; (B) neither the Company nor its subsidiaries have been notified of, and each of them have no knowledge of any event or condition that could result in, any security breach or incident, unauthorized access or disclosure or other compromise to their IT Systems and Data that would, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; and (C) the Company and its subsidiaries have implemented appropriate controls, policies, procedures, and technological safeguards to maintain and protect the

integrity, continuous operation, redundancy and security of their IT Systems and Data as required by applicable regulatory standards. The Company and its subsidiaries are presently in compliance with all applicable laws or statutes and all applicable judgments, orders, rules and regulations of any court or arbitrator or governmental or regulatory authority, internal policies and contractual obligations relating to the privacy and security of IT Systems and Data.

(liii) Chandler Merger Agreement. Reference is hereby made to that Merger Agreement by and between the Company and Chandler. Nothing has come to the Company’s attention that would cause it to believe that the representations and warranties of each of the Company or Chandler as set forth in the Merger Agreement and qualified by the corresponding disclosure schedules are not true and correct in all material respects (except for such representations and warranties subject to a materiality qualifier, in which case such representations and warranties are not true in all respects) or that the Company or Chandler will not comply in all material respects with the covenants therein applicable to it.

(b) Representations and Warranties Related to the Bank. The Bank represents and warrants to, and agrees with, each of the Underwriters as of the date hereof, as of the Closing Time referred to in Section 2(c) hereof, and as of each Date of Delivery (if any) referred to in Section 2(b) hereof, as follows:

(i) The Bank is duly chartered and is validly existing as a Texas state savings bank and is in good standing under the laws of the State of Texas and has been duly qualified as a foreign bank for the transaction of business and is in good standing under the laws of each other jurisdiction in which it owns, leases or operates properties or conducts any business so as to require such qualification or is subject to no material liability or disability by reason of the failure to be so qualified, except where such failure would not reasonably be expected to have a material adverse effect on the business, business prospects, management, financial position, shareholders’ equity or results of operations of the Bank. The Bank is the only Significant Subsidiary of the Company and does not itself have any subsidiaries other than those listed in ScheduleD-2.

(ii) Neither the Bank nor any of its subsidiaries is (A) in violation of its respective articles of incorporation or bylaws (or other organization documents), (B) in violation of any law, ordinance, administrative or governmental rule or regulation applicable to the Bank, or (C) in default in the performance of any obligation, agreement or condition contained in any bond, debenture, note or any other evidence of indebtedness or in any agreement, indenture, lease or other instrument to which the Bank or its subsidiaries is a party or by which any of them or any of their respective properties may be bound (collectively, the “Bank Instruments”), except, in the case of (B) and (C) above, where any such violation or default, individually or in the aggregate, would not reasonably be expected to have a material adverse effect on the business, business prospects, management, financial position, shareholders’ equity or results of operations of the Bank.

(iii) The Bank has the corporate power and authority to own, lease and operate its properties and to conduct its business as described in the General Disclosure Package and the Prospectus and to enter into and perform its obligations under this Agreement. The Bank is the only depository institution subsidiary of the Company and the activities of the Bank and its subsidiaries are permitted under the laws and regulations of the State of Texas and the FDIC and the deposit accounts in the Bank are insured up to the applicable limits by the FDIC and no proceeding for the termination or revocation of such insurance is pending or, to the knowledge of the Company, threatened against the Bank.

(iv) The execution, delivery and performance of this Agreement by the Bank, compliance by the Bank with all of the provisions of this Agreement and the consummation of the transactions herein contemplated do not and will not contravene, conflict with, or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any Bank Instrument, except

for such contraventions, conflicts, breaches or violations that would not, individually or in the aggregate, result in a material adverse effect on the business, business prospects, management, financial position, shareholders’ equity or results of operations of the Bank, nor does or will any such action contravene, conflict with or result in a breach or violation of any of the terms or provisions of the articles of incorporation or association orby-laws of the Bank or any statute, order, law, rule, regulation or decree of any court or governmental agency or body having jurisdiction over the Bank or any of its subsidiaries or any of their properties, except for violations of statutes, orders, laws, rules, regulations or decrees that could not, individually or in the aggregate, result in a material adverse effect on the business, business prospects, management, financial position, shareholders’ equity or results of operations of the Bank or in the ability of the Bank to perform its obligations under this Agreement.

(v) This Agreement has been duly authorized, executed and delivered by the Bank.

(c) Officer’s Certificates. Any certificate signed by any officer of the Company or any of its subsidiaries delivered to the Underwriters or to counsel for the Underwriters shall be deemed a representation and warranty by the Company to the Underwriters as to the matters covered thereby.

SECTION 2. Sale and Delivery to Underwriters; Closing.

(a) Firm Shares. On the basis of the representations and warranties herein contained and subject to the terms and conditions set forth herein, the Company agrees to sell to each of the Underwriters and the Underwriters agree, severally and not jointly, to purchase from the Company, at the price per share set forth in Schedule C, the respective number of Firm Shares set forth in Schedule A opposite its name.

(b) Option Shares. In addition, on the basis of the representations and warranties herein contained and subject to the terms and conditions set forth herein, the Company hereby grants an option to the Underwriters to purchase, severally and not jointly, up to an additional 300,000 shares of Common Stock, at the price per share set forth in Schedule C. The option hereby granted may be exercised in whole or in part from time to time through the 30th day after the date of this Agreement, upon notice by the Representatives to the Company setting forth the number of Option Shares as to which the several Underwriters are then exercising the option and the time and date of payment and delivery for such Option Shares. Any such time and date of delivery (each, a “Date of Delivery”) shall be determined by the Representatives, but shall not be later than seven full business days after the exercise of said option, nor in any event prior to the Closing Time, as hereinafter defined. If the option is exercised as to all or any portion of the Option Shares, each of the Underwriters, acting severally and not jointly, will purchase that proportion of the total number of Option Shares then being purchased which the number of Firm Shares set forth in Schedule A opposite the name of such Underwriter bears to the total number of Firm Shares, subject, in each case, to such adjustments as the Representatives in their sole discretion shall make to eliminate any sales or purchases of fractional shares.

(c) Payment. Payment of the purchase price for, and delivery of certificates for, the Firm Shares shall be made at the offices of Covington & Burling LLP, One CityCenter, 850 Tenth Street, N.W., Washington, D.C. 20001, or at such other place as shall be agreed upon by the Representatives and the Company, at 10:00 a.m. (Eastern Time) on the second (third, if the pricing occurs after 4:30 p.m. (Eastern Time) on any given day) business day after the date hereof, or such other time not later than ten business days after such date as shall be agreed upon by the Representatives and the Company (such time and date of payment and delivery being herein called “Closing Time”).

In addition, in the event that any or all of the Option Shares are purchased by the Underwriters, payment of the purchase price for, and delivery of certificates for, such Option Shares shall be made at theabove-mentioned offices, or at such other place as shall be agreed upon by the Representatives and the Company, on each Date of Delivery as specified in the notice from the Representatives to the Company.

Payment shall be made to the Companyby wire transfer of immediately available funds to a bank account designated by the Companyagainst delivery of the Shares to the Representatives through the facilities of the Depository Trust Company (“DTC”) for the respective accounts of the Underwriters.

(d) Denominations; Registration. Certificates for the Firm Shares and the Option Shares, if any, shall be in such denominations and registered in such names as the Representatives may request in writing at least one full business day before the Closing Time or the relevant Date of Delivery, as the case may be. The certificates for the Firm Shares and the Option Shares, if any, will be made available for examination and packaging by the Representatives in the District of Columbia not later than 10:00 a.m. (Eastern Time) on the business day prior to the Closing Time or the relevant Date of Delivery, as the case may be.

SECTION 3. Covenants of the Company. The Company covenants and agrees with each of the Underwriters as follows:

(a) Compliance with Securities Regulations and Commission Requests. The Company, subject to Section 3(b), will comply with the requirements of Rule 430A or Rule 430B, as applicable, and will notify the Representatives immediately, and confirm the notice in writing, (i) when any post-effective amendment to the Registration Statement shall become effective, or any preliminary prospectus or any amended Prospectus shall have been filed, (ii) of the receipt of any comments from the Commission, (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or for additional information, (iv) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement, any Rule 462(b) Registration Statement or any respective post-effective amendment thereto or of any order preventing or suspending the use of the Base Prospectus, any preliminary prospectus, or the Prospectus, or of the suspension of the qualification of the Shares for offering or sale in any jurisdiction, or of the initiation or threatening of any proceedings for any of such purposes or of any examination pursuant to Section 8(e) of the 1933 Act concerning the Registration Statement and (v) if the Company becomes the subject of a proceeding under Section 8A of the 1933 Act in connection with the offering of the Shares. The Company will promptly effect the filings necessary pursuant to Rule 424(b) in the manner and within the time period required by Rule 424(b) (without reliance on Rule 424(b)(8)) and will take such steps as it deems necessary to ascertain promptly whether the form of prospectus transmitted for filing under Rule 424(b) was received for filing by the Commission and, in the event that it was not, it will promptly file such prospectus. The Company will make every reasonable effort to prevent the issuance of any stop order and, if any stop order is issued, to obtain the lifting thereof at the earliest possible moment.

(b) Filing of Amendments. The Company will give the Representatives notice of its intention to file or prepare any amendment or supplement to the Registration Statement (including any filing under Rule 462(b) of the 1933 Act Regulations), the Base Prospectus, any preliminary prospectus, or the Prospectus, whether pursuant to the 1933 Act, the 1934 Act or otherwise, will furnish the Representatives with copies of any such documents a reasonable amount of time prior to such proposed filing or use, as the case may be, and will not file or use any such document to which the Representatives or counsel for the Underwriters shall object.

(c) Delivery of Registration Statement. The Company has made available or will deliver to the Representatives and counsel for the Underwriters, without charge, conformed copies of the Registration Statement as originally filed and of each amendment thereto (including exhibits filed therewith or incorporated

by reference therein and documents incorporated or deemed to be incorporated by reference therein) and conformed copies of all consents and certificates of experts, and will also deliver to the Representatives, without charge, a conformed copy of the Registration Statement as originally filed and of each amendment thereto (without exhibits) for each of the Underwriters. The copies of the Registration Statement and each amendment thereto furnished to each Underwriter will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by RegulationS-T.

(d) Delivery of Prospectuses. The Company has delivered to each Underwriter, without charge, as many copies of the Base Prospectus and any preliminary prospectus as such Underwriter reasonably requested, and the Company hereby consents to the use of such copies for purposes permitted by the 1933 Act. The Company will furnish to each Underwriter, without charge, during the period when the Prospectus is required to be delivered under the 1933 Act or the 1934 Act, such number of copies of the Prospectus (as amended or supplemented) as such Underwriter may reasonably request. The Prospectus and any amendments or supplements thereto furnished to each Underwriter will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by RegulationS-T.

(e) Continued Compliance with Securities Laws. The Company will comply with the 1933 Act and the 1933 Act Regulations and the 1934 Act and the 1934 Act Regulations so as to permit the completion of the distribution of the Shares as contemplated in this Agreement and in the Registration Statement, the General Disclosure Package and the Prospectus. If at any time when a prospectus is (or, but for the exception afforded by Rule 172 of the 1933 Act Regulations, would be) required by the 1933 Act (or in lieu thereof the notice referred to in Section 173(a) of the 1933 Act Regulations) to be delivered in connection with sales of the Shares ending no later than nine months from the date hereto (the “Delivery Period”), any event shall occur or condition shall exist as a result of which it is necessary, in the opinion of counsel for the Underwriters or for the Company, to (i) amend the Registration Statement in order that the Registration Statement will not include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) amend or supplement the Prospectus in order that the Prospectus will not include any untrue statements of a material fact or omit to state a material fact necessary in order to make the statements therein not misleading in the light of the circumstances existing at the time it (or in lieu thereof the notice referred to in Section 173(a) of the 1933 Act Regulations) is delivered to a purchaser, or (iii) if it shall be necessary, in the opinion of such counsel, at any such time to amend the Registration Statement or amend or supplement the Prospectus in order to comply with the requirements of the 1933 Act or the 1933 Act Regulations, the Company will promptly (A) give the Representatives written notice of such event or condition, (B) prepare and file with the Commission, subject to Section 3(b) of this Agreement, such amendment or supplement as may be necessary to correct such statement or omission or to make the Registration Statement or the Prospectus comply with such requirements and use its best efforts to have any amendment to the Registration Statement declared effective by the Commission as soon as possible, and (C) furnish to each Underwriter such number of copies of such amendment or supplement as such Underwriter may reasonably request. If at any time following issuance of an Issuer-Represented Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer-Represented Free Writing Prospectus conflicted or would conflict with the information contained in the Registration Statement or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at that subsequent time, not misleading, the Company has promptly notified or will promptly notify the Representatives and has promptly amended or will promptly amend or supplement, at its own expense, such Issuer-Represented Free Writing Prospectus to eliminate or correct such conflict, untrue statement or omission.

(f) Blue Sky Qualifications. The Company will use its best efforts, in cooperation with the Underwriters, to qualify the Shares for offering and sale under the applicable securities laws of such states and other jurisdictions (domestic or foreign) as the Representatives may designate and to maintain such qualifications in effect for the Delivery Period; provided, that the Company shall not be obligated to file any general consent to service of process or to qualify as a foreign corporation or as a dealer in securities in any jurisdiction in which it is not so qualified or to subject itself to taxation in respect of doing business in any jurisdiction in which it is not otherwise so subject. In each jurisdiction in which the Shares have been so qualified, the Company will file such statements and reports as may be required by the laws of such jurisdiction to continue such qualification in effect for the Delivery Period. The Company will also supply the Underwriters with such information as is necessary for the determination of the legality of the Shares for investment under the laws of such jurisdiction as such Underwriter may request.

(g) Earning Statement. The Company will timely file such reports pursuant to the 1934 Act as are necessary in order to make generally available to its securityholders as soon as practicable, but in any event not later than 16 months after the effective date of the Registration Statement, an earning statement (as defined and in the form complying with the provisions of Rule 158 of the 1933 Act Regulations and satisfying the provisions of Section 11(a) of the 1933 Act).

(h) Use of Proceeds. The Company will use the net proceeds received by it from the sale of the Shares in the manner specified in the Prospectus under “Use of Proceeds.”

(i) Listing. The Company will use its best efforts to maintain listing of the Shares on Nasdaq and will file with Nasdaq all documents and notices required by Nasdaq.

(j) Restriction on Sale of Shares. During a period of 90 days from the date of the Prospectus (the“Lock-Up Period”), the Company will not, without the prior written consent of the Representatives, directly or indirectly, (i) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of, hypothecate, establish an open “put equivalent position” within the meaning of Rule16a-1(h) of the 1934 Act Regulations, or otherwise dispose of or transfer any shares of the Company’s Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, or file any registration statement under the 1933 Act with respect to any of the foregoing or (ii) enter into any swap, hedge or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Common Stock, whether any such swap, hedge or transaction described in clause (i) or (ii) above is to be settled by delivery of shares of Common Stock or other securities, in cash or otherwise. The foregoing sentence shall not apply to (A) the Shares to be sold hereunder, (B) any shares of Common Stock issued by the Company upon the exercise of an option or warrant or the conversion of a security outstanding on the date hereof and referred to in the Prospectus, or (C) any shares of Common Stock issued or options to purchase Common Stock granted pursuant to existing employee benefit plans of the Company referred to in the Prospectus provided that such options shall not be vested and exercisable within the90-day period referred to above. The Company also agrees that during theLock-Up Period, other than for the sale of Common Stock hereunder, the Company will not file any registration statement, preliminary prospectus or prospectus, or any amendment or supplement thereto, under the 1933 Act for any such transaction or which registers, or offers for sale, Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, except for any registration statement on FormS-8 relating to employee benefit plans and any registration statement on FormS-4 concerning the Merger Agreement and the transactions contemplated thereby.

(k) Reporting Requirements. The Company, during the period when the Prospectus is required to be delivered under the 1933 Act or the 1934 Act, will file all documents required to be filed by the Company with the Commission pursuant to the 1934 Act within the time periods required by the 1934 Act and the 1934 Act Regulations.

(l) Lock-up Agreements. The Company agrees to enforce its rights under any of its existing registration rights agreements and/or shareholders’ agreement to restrict the transfer of securities within the90-day period following the Closing Time.

(m) Issuer Free Writing Prospectus. The Company represents and agrees that, unless it obtains the prior consent of the Representatives, it has not made and will not make any offer relating to the Shares that would constitute an “issuer free writing prospectus,” as defined in Rule 433, or that would otherwise constitute a “free writing prospectus,” as defined in Rule 405, required to be filed with the Commission. Any such free writing prospectus consented to by the Representatives is hereinafter referred to as a “Permitted Issuer Free Writing Prospectus.” The Company represents that it has treated or agrees that it will treat each Permitted Issuer Free Writing Prospectus as an “issuer free writing prospectus,” as defined in Rule 433, and has complied and will comply with the requirements of Rule 433 applicable to any Permitted Issuer Free Writing Prospectus, including timely filing with the Commission where required, legending and record keeping.

(n) DTC. The Company will cooperate with the Representatives and use its best efforts to permit the Shares to be eligible for clearance, settlement and trading through the facilities of DTC, if required.

(o) Emerging Growth Company. The Company will promptly notify the Representatives if the Company ceases to be an Emerging Growth Company at any time prior to completion of the distribution of the Shares within the meaning of the 1933 Act.

SECTION 4. Payment of Expenses.

(a) Expenses. Whether or not the transactions contemplated in this Agreement are consummated or this Agreement is terminated, the Company will pay or cause to be paid all expenses incident to the performance of its obligations under this Agreement, including (i) the preparation, printing and filing of the Registration Statement (including financial statements and exhibits) as originally filed and of each amendment thereto, (ii) the preparation, printing and delivery to the Underwriters of this Agreement and such other documents as may be required in connection with the offering, purchase, sale, issuance or delivery of the Shares, (iii) the preparation, issuance and delivery of the certificates for the Shares to the Underwriters, including any stock or other transfer taxes and any stamp or other duties payable upon the sale, issuance or delivery of the Shares to the Underwriters, (iv) the fees and disbursements of the Company’s counsel, accountants and other advisors, (v) the qualification of the Shares under securities laws in accordance with the provisions of Section 3(f) hereof, including filing fees and the reasonable fees and disbursements of counsel for the Underwriters in connection therewith and in connection with the preparation, printing and delivery to the Underwriters of the Blue Sky Survey and any supplement thereto and the fees and expenses of making the Shares eligible for clearance, settlement and trading through the facilities of DTC, if required, (vi) the printing and delivery to the Underwriters of copies of the Base Prospectus, any preliminary prospectus supplement, any Permitted Issuer Free Writing Prospectus and the Prospectus, and any amendments or supplements thereto (including any costs associated with electronic delivery of these materials), (vii) the fees and expenses of any transfer agent or registrar for the Shares, (viii) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the Shares, including without limitation, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations, travel and lodging expenses of the

representatives and officers of the Company and any such consultants, and the cost of aircraft and other transportation chartered in connection with the road show, (ix) certainout-of-pocket expenses incurred by the Underwriters in connection with the offering of the Shares, including the reasonable fees and disbursements of counsel to the Underwriters in connection with determining the compliance of the terms of the sale of the Shares with the rules and regulations of FINRA in an aggregate amount not to exceed $100,000, and (x) the fees and expenses incurred in connection with the listing of the Shares on Nasdaq.

(b) Termination of Agreement. If this Agreement is terminated by the Representatives in accordance with the provisions of Section 5 or Section 9(a) hereof, the Company shall reimburse the Underwriters for all of theirout-of-pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriters in an aggregate amount not to exceed $100,000.

SECTION 5. Conditions of the Underwriters’ Obligations. The obligations of the Underwriters hereunder are subject to the accuracy of the representations and warranties of the Company contained in Section 1 hereof and in certificates of any officer of the Company or any subsidiary of the Company delivered pursuant to the provisions hereof, to the performance by the Company of its covenants and other obligations hereunder, and to the following further conditions:

(a) Effectiveness of Registration Statement. The Registration Statement, including any Rule 462(b) Registration Statement, is effective and at the Closing Time no stop order suspending the effectiveness of the Registration Statement shall have been issued under the 1933 Act or proceedings for that purpose have been instituted or are pending or, to the Company’s knowledge, are contemplated by the Commission, and any request on the part of the Commission for additional information shall have been complied with to the reasonable satisfaction of counsel to the Underwriters, no notice of objection to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) of the 1933 Act Regulations shall have been received by the Company, no order preventing or suspending the use of any preliminary prospectus or the Prospectus or any amendment or supplement thereto shall have been issued and no proceedings for any of those purposes shall have been instituted, shall be pending or, to the Company’s knowledge, shall be contemplated. Each preliminary prospectus, each Issuer Free Writing Prospectus and the Prospectus containing the Rule 430 Information shall have been filed with the Commission in the manner required by Rule 424(b) (without reliance on Rule 424(b)(8)) and Rule 433, as applicable, within the time period prescribed by, and in compliance with, the 1933 Act Regulations (or a post-effective amendment providing such information shall have been filed and declared effective in accordance with the requirements of Rule 430A or Rule 430B).

(b) Opinion of Counsel for Company. At the Closing Time, the Representatives shall have received the favorable opinion, dated as of Closing Time, of Hunton Andrews Kurth LLP, counsel for the Company, in form and substance satisfactory to counsel for the Underwriters.

(c) Opinion of Counsel for Underwriters. At the Closing Time, the Representatives shall have received the favorable opinion, dated as of Closing Time, of Covington & Burling LLP, counsel for the Underwriters, in form and substance satisfactory to the Representatives.

(d) Officers’ Certificate. At the Closing Time, there shall not have been, since the date hereof or since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package, or the Prospectus, any Material Adverse Effect, and the Representatives shall have received a certificate of the Chief Executive Officer, the President or a Vice President of the Company and of the Chief Financial Officer or chief accounting officer of the Company, dated as of Closing Time, to the effect that (i) there has been no Material Adverse Effect since such dates, (ii) the representations and warranties in Section 1(a) and Section 1(b) hereof are true and correct with the same force and effect as though expressly made at and as of Closing Time, (iii) the Company has complied

with all agreements and satisfied all conditions on its part to be performed or satisfied at or prior to Closing Time, and (iv) no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings for that purpose have been instituted or are pending or, to their knowledge, are contemplated by the Commission.

(e) Accountants’ Comfort Letter. At the time of the execution of this Agreement, the Representatives shall have received from each of (A) BDO, with respect to the Company and (B) BKD, with respect to Beeville, a letter dated such date, in form and substance satisfactory to the Representatives, together with signed or reproduced copies of such letter for each of the other Underwriters confirming that they are a registered public accounting firm and independent registered public accountants as required by the 1933 Act and containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement and the Prospectus , including, in the BDO letter, compliance of the pro forma financial statements included in the Company’s Current Report on Form8-K/A filed on May 28, 2019 with Rule11-02 of RegulationS-X and confirmation that nothing came to their attention which caused them to believe that, during the period from the date of the unaudited amounts shown in the Company’s Quarterly Report on Form10-Q filed with the Commission on May 10, 2019 to thecut-off date of no more than three business days prior to delivery thereof, there was any change in the capital stock, short-term debt, long-term debt or deposits of the consolidated Company.

(f) Bring-down Comfort Letter. At the Closing Time the Representatives shall have received from each of (A) BDO, with respect to the Company and (B) BKD, with respect to Beeville, a letter dated as of the Closing Time, to the effect that they reaffirm the statements made in the letter furnished pursuant to subsection (e) of this Section 5, except that the specified date referred to shall be a date not more than three business days prior to Closing Time.

(g) Certificate of Chief Financial Officer.At the time of the execution of this Agreement and at the Closing Time, the Representatives shall have received a certificate executed by the Chief Financial Officer of the Company, in form and substance reasonably satisfactory to the Representatives.

(h) Approval of Listing. The Common Stock (including the Shares) is registered pursuant to Section 12(b) of the 1934 Act and is listed on Nasdaq, and the Company has taken no action designed to, or likely to have the effect of, terminating the registration of the Common Stock under the 1934 Act or delisting the Common Stock from Nasdaq, nor has the Company received any notification that the Commission or Nasdaq is contemplating terminating such registration or listing.

(i) No Objection. FINRA shall have raised no objection with respect to the fairness and reasonableness of the underwriting terms and arrangements.

(j) Lock-up Agreements. At the date of this Agreement, the Representatives shall have received an agreement substantially in the form of Exhibit A hereto signed by the persons listed on Schedule E hereto.

(k) Delivery of Prospectus. The Company shall have complied with the provisions hereof with respect to the furnishing of prospectuses, in electronic or printed format, on the New York business day next succeeding the date of this Agreement.

(l) Financial Crimes Enforcement Network. On or before the date of this Agreement, the Representatives shall have received a certificate satisfying the beneficial ownership due diligence requirements of the Financial Crimes Enforcement Network from the Company that is not an individual in form and substance satisfactory to the Representatives.

(m) No Termination Event. On or after the date hereof, there shall not have occurred any of the events, circumstances or occurrences set forth in Section 9(a) hereof.

(n) Conditions to Purchase of Option Shares. In the event that the Underwriters exercise their option provided in Section 2(b) hereof to purchase all or any portion of the Option Shares, the representations and warranties of the Company contained herein and the statements in any certificates furnished by the Company and any subsidiary of the Company hereunder shall be true and correct as of each Date of Delivery and, at the relevant Date of Delivery, the Representatives shall have received:

(i) Officers’ Certificate. A certificate, dated such Date of Delivery, of the Chief Executive Officer, President or a Vice President of the Company and of the Chief Financial Officer or chief accounting officer of the Company confirming that the certificate delivered at the Closing Time pursuant to Section 5(d) hereof remains true and correct as of such Date of Delivery.

(ii) Opinion of Counsel for Company. The favorable opinion of Hunton Andrews Kurth LLP, counsel for the Company, in form and substance satisfactory to counsel for the Underwriters, dated such Date of Delivery, relating to the Option Shares to be purchased on such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(b) hereof.

(iii) Opinion of Counsel for Underwriters. The favorable opinion of Covington & Burling LLP, counsel for the Underwriters, dated such Date of Delivery, relating to the Option Shares to be purchased on such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(c) hereof.

(iv) Bring-down Comfort Letter. A letter from each of (A) BDO, with respect to the Company and (B) BKD, with respect to Beeville, in form and substance satisfactory to the Representatives and dated such Date of Delivery, substantially in the same form and substance as the letter furnished to the Representatives pursuant to Section 5(f) hereof, except that the “specified date” in the letter furnished pursuant to this paragraph shall be a date not more than five days prior to such Date of Delivery.

(v) Certificate of Chief Financial Officer.A certificate executed by the Chief Financial Officer of the Company, dated as of such Date of Delivery, in form and substance reasonably satisfactory to the Representatives.

(vi) No Termination Event. There shall not have occurred prior to the Date of Delivery any of the events, circumstances or occurrences set forth in Section 9(a) hereof.

(o) Additional Documents. At the Closing Time and at each Date of Delivery counsel for the Underwriters shall have been furnished with such documents and opinions as they may require for the purpose of enabling them to pass upon the issuance and sale of the Shares as herein contemplated, or in order to evidence the accuracy of any of the representations or warranties, or the fulfillment of any of the conditions, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Shares as herein contemplated shall be satisfactory in form and substance to the Representatives and counsel for the Underwriters.

If any condition specified in this Section 5 shall not have been fulfilled when and as required to be fulfilled, this Agreement, or, in the case of any condition to the purchase of Option Shares on a Date of Delivery which is after the Closing Time, the obligations of the several Underwriters to purchase the relevant Option Shares, may be terminated by the Representatives by notice to the Company at any time at or prior to Closing Time or such Date of Delivery, as the case may be, and such termination shall be without liability of any party hereto to any other party hereto except as provided in Section 4 hereof and except that Sections 1, 6, 7, 8, 15, 16, 17 and 18 hereof shall survive any such termination and remain in full force and effect.

SECTION 6. Indemnification.

(a) Indemnification of Underwriters. The Company agrees to indemnify and hold harmless each Underwriter, its affiliates (as such term is defined in Rule 501(b) of the 1933 Act Regulations) (“Affiliates”), its selling agents, directors, officers and each person, if any, who controls any Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act to the extent and in the manner set forth in clauses (i), (ii) and (iii) below:

(i) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, arising out of any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or any amendment thereto), including the Rule 430 Information, if applicable, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading or arising out of any untrue statement or alleged untrue statement of a material fact included in the Base Prospectus, any preliminary prospectus, the Prospectus, the General Disclosure Package or any Issuer-Represented Free Writing Prospectus or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

(ii) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, to the extent of the aggregate amount paid in settlement of any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or of any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission; provided that (subject to Section 6(d) below) any such settlement is effected with the written consent of the Company; and

(iii) against any and all expense whatsoever, as incurred (including the fees and disbursements of counsel chosen by the Representatives), reasonably incurred in investigating, preparing or defending against, or appearing as a witness or providing information or documents in connection with, any litigation or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission to the extent that any such expense is not paid under (i) or (ii) above;

provided, that this indemnity agreement shall not apply to any loss, liability, claim, damage or expense to the extent arising out of any untrue statement or omission or alleged untrue statement or omission made in the Registration Statement, the Base Prospectus, any preliminary prospectus, the Prospectus, the General Disclosure Package or any Issuer-Represented Free Writing Prospectus in reliance upon and in conformity with the Underwriter Information.

(b) Indemnification of Company, Directors and Officers. Each Underwriter severally, and not jointly, agrees to indemnify and hold harmless the Company, its directors, each of its officers who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act, against any and all loss, liability, claim, damage and expense described in the indemnity contained in subsection (a) of this Section, as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made

in the Registration Statement (or any amendment thereto), including the Rule 430 Information, if applicable, or the Base Prospectus, any preliminary prospectus, the Prospectus, the General Disclosure Package or any Issuer-Represented Free Writing Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with the written information furnished to the Company through the Representatives by or on behalf of that Underwriter specifically for use therein, which information the parties hereto agree is limited to the Underwriter Information.

(c) Actions against Parties; Notification. Each indemnified party shall give notice as promptly as reasonably practicable to each indemnifying party of any action commenced against it in respect of which indemnity may be sought hereunder, but failure to so notify an indemnifying party shall not relieve such indemnifying party from any liability hereunder to the extent it is not materially prejudiced as a result thereof and in any event shall not relieve it from any liability which it may have otherwise than on account of this indemnity agreement. In the case of parties indemnified pursuant to Section 6(a) above, counsel to the indemnified parties shall be selected by the Representatives, and, in the case of parties indemnified pursuant to Section 6(b) above, counsel to the indemnified parties shall be selected by the Company. An indemnifying party may participate at its own expense in the defense of any such action; provided, that counsel to the indemnifying party shall not (except with the consent of the indemnified party) also be counsel to the indemnified party. In no event shall the indemnifying parties be liable for fees and expenses of more than one counsel (in addition to any local counsel) separate from their own counsel for all indemnified parties in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances. No indemnifying party shall, without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of any judgment with respect to any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever in respect of which indemnification or contribution could be sought under this Section 6 or Section 7 hereof (whether or not the indemnified parties are actual or potential parties thereto), unless such settlement, compromise or consent (i) includes an unconditional release of each indemnified party from all liability arising out of such litigation, investigation, proceeding or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party.

(d) Settlement Without Consent if Failure to Reimburse. If at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by Section 6(a)(ii) effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by such indemnifying party of the aforesaid request, (ii) such indemnifying party shall have received notice of the terms of such settlement at least 30 days prior to such settlement being entered into and (iii) such indemnifying party shall not have reimbursed such indemnified party in accordance with such request prior to the date of such settlement.

SECTION 7. Contribution. If the indemnification provided for in Section 6 hereof is for any reason unavailable to or insufficient to hold harmless an indemnified party in respect of any losses, liabilities, claims, damages or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount of such losses, liabilities, claims, damages and expenses incurred by such indemnified party, as incurred, (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Shares pursuant to this Agreement or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company on the one hand and of the Underwriters on the other hand in connection with the statements or omissionswhich resulted in such losses, liabilities, claims, damages or expenses, as well as any other relevant equitable considerations.

The relative benefits received by the Company on the one hand and the Underwriters on the other hand in connection with the offering of the Shares pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the offering of the Shares pursuant to this Agreement (before deducting expenses) received by the Company, on the one hand, and the total underwriting discount and commissions received by the Underwriters, on the other hand, in each case as set forth on the cover of the Prospectus, bear to the aggregate public offering price of the Shares as set forth on the cover of the Prospectus.

The relative fault of the Company, on the one hand, and the Underwriters, on the other hand, shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The Company and each Underwriter agree that it would not be just and equitable if contribution pursuant to this Section 7 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this Section 7. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and referred to above in this Section 7 shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission.

Notwithstanding the provisions of this Section 7, no Underwriter shall be required to contribute any amount in excess of the underwriting discount received by such Underwriter in connection with the Shares underwritten by it and distributed to the public.

No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the 1933 Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations in this Section 7 to contribute are several in proportion to their respective underwriting obligations and not joint.

For purposes of this Section 7, each person, if any, who controls an Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act and such Underwriter’s Affiliates and selling agents shall have the same rights to contribution as such Underwriter, and each director of the Company, each officer of the Company who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act shall have the same rights to contribution as the Company.

SECTION 8. Representations, Warranties and Agreements to Survive Delivery. The indemnity and contribution provisions contained in Section 6 and Section 7 hereof and all representations, warranties and agreements contained in this Agreement or in certificates of officers of the Company or any of its subsidiaries submitted pursuant hereto, shall remain operative and in full force and effect, regardless of any (i) investigation made by or on behalf of any Underwriter or its Affiliates or selling agents, any person controlling any Underwriter, its officers or directors, or by or on behalf of the Company, and (ii) delivery of and payment for the Shares.

SECTION 9. Termination of Agreement.

(a) Termination; General. The Representatives may terminate this Agreement, by notice to the Company, at any time at or prior to Closing Time (i) if there has been, since the time of execution of this Agreement or since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package or the Base Prospectus, any preliminary prospectus or the Prospectus, any Material Adverse Effect in the judgment of the Representatives or if the Underwriters shall decline to purchase the Shares for any reason permitted under this Agreement; (ii) if there has occurred any material adverse change in the financial markets in the United States or the international financial markets, any outbreak of hostilities or escalation thereof or other calamity or crisis or any change or development involving a prospective change in national or international political, financial or economic conditions, including, without limitation, as a result of terrorist activities, in each case the effect of which is such as to make it, in the judgment of the Representatives, impracticable or inadvisable to market the Shares or to enforce contracts for the sale of the Shares, (iii) there shall not have been any decrease in or withdrawal of the rating of any debt securities or preferred securities of the Company or any of its subsidiaries by any “nationally recognized statistical rating organization” (as defined for purposes of Section 3(a)(62) of the 1934 Act) or any notice given of any intended or potential decrease in or withdrawal of any such rating or of a possible change in any such rating that does not indicate the direction of the possible change, (iv) if trading in any securities of the Company has been suspended or materially limited by the Commission or Nasdaq, or if trading generally on the New York Stock Exchange or Nasdaq has been suspended or materially limited, or minimum or maximum prices for trading have been fixed, or maximum ranges for prices have been required, by any of said exchanges or by order of the Commission, FINRA or any other governmental authority, (v) a material disruption has occurred in commercial banking or securities settlement or clearance services in the United States or with respect to Clearstream or Euroclear Systems in Europe, or (vi) if a general moratorium on commercial banking activities has been declared by federal, New York or Texas authorities.

(b) Liabilities. If this Agreement is terminated pursuant to this Section 9, such termination shall be without liability of any party to any other party except as provided in Section 4 hereof, and provided further that Sections 1, 6, 7, 8, 15, 16, 17 and 18 shall survive such termination and remain in full force and effect.

SECTION 10. Default by One or More of the Underwriters. If one or more of the Underwriters shall fail at the Closing Time or a Date of Delivery to purchase the Shares which it or they are obligated to purchase under this Agreement (the “Defaulted Securities”), the Representatives shall have the right, within 24 hours thereafter, to make arrangements for one or more of thenon-defaulting Underwriters, or any other underwriters, to purchase all, but not less than all, of the Defaulted Securities in such amounts as may be agreed upon and upon the terms herein set forth; if, however, the Representatives shall not have completed such arrangements within such24-hour period, then:

(i) if the number of Defaulted Securities does not exceed 10% of the number of Shares to be purchased on such date, each of thenon-defaulting Underwriters shall be obligated, severally and not jointly, to purchase the full amount thereof in the proportions that their respective underwriting obligations hereunder bear to the underwriting obligations of allnon-defaulting Underwriters; or

(ii) if the number of Defaulted Securities exceeds 10% of the number of Shares to be purchased on such date, this Agreement or, with respect to any Date of Delivery which occurs after the Closing Time, the obligation of the Underwriters to purchase, and the Company to sell, the Option Shares to be purchased and sold on such Date of Delivery shall terminate without liability on the part of anynon-defaulting Underwriter.

No action taken pursuant to this Section 10 shall relieve any defaulting Underwriter from liability in respect of its default.

In the event of any such default which does not result in a termination of this Agreement or, in the case of a Date of Delivery which is after the Closing Time, which does not result in a termination of the obligation of the Underwriters to purchase and the Company to sell the relevant Option Shares, as the case may be, either the Representatives or the Company shall have the right to postpone Closing Time or the relevant Date of Delivery, as the case may be, for a period not exceeding seven days in order to effect any required changes in the Registration Statement, the General Disclosure Package or the Prospectus or in any other documents or arrangements. As used herein, the term “Underwriter” includes any person substituted for an Underwriter under this Section 10.

SECTION 11. Use of Free Writing Prospectuses by Underwriters. Each Underwriter represents and agrees that, unless it obtains the prior consent of the Company and the Representatives, it has not made and will not make any offer relating to the Shares that would constitute an “issuer free writing prospectus,” as defined in Rule 433, or that would otherwise constitute a “free writing prospectus,” as defined in Rule 405, required to be filed with the Commission.

SECTION 12. Notices. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted by any standard form of telecommunication. Notices to the Underwriters shall be directed to the Representatives at Stephens Inc., 111 Center Street, Little Rock, Arkansas 72201, Attention: Prospectus Department (fax no. (501)377-2131) and Keefe, Bruyette & Woods, Inc., 787 Seventh Avenue, 4th Floor, New York, New York 10019, Attention: Equity Capital Markets (fax no. (212)582-1592), with a copy (which shall not constitute notice) to Covington & Burling LLP, One CityCenter, 850 Tenth Street, N.W., Washington, D.C. 20001, Attention: Michael P. Reed (fax no. (202)778-5988) and Christopher DeCresce (fax no. (646)441-9017). Notices to the Company shall be directed to it at Spirit of Texas Bancshares, Inc., 1836 Spirit of Texas Way, Conroe, Texas 77301, Attention: Dean O. Bass (fax. no. (281)516-4921), with a copy (which shall not constitute notice) to Hunton Andrews Kurth LLP, 1445 Ross Avenue, Suite 3700, Dallas, Texas 75202, Attention: Peter G. Weinstock (fax. no. (214)740-7182).

SECTION 13. Parties. This Agreement shall inure to the benefit of and be binding upon the Underwriters, the Company, the Bank and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, firm or corporation, other than the Underwriters, the Company and their respective successors and the indemnified parties referred to in Sections 6 and 7 hereof and their heirs and legal representatives, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. This Agreement and all conditions and provisions hereof are intended to be for the sole and exclusive benefit of the Underwriters, the Company, the Bank and their respective successors, and said controlling persons and officers and directors and their heirs and legal representatives, and for the benefit of no other person, firm or entity. No purchaser of Shares from any Underwriter shall be deemed to be a successor by reason merely of such purchase.

SECTION 14. No Fiduciaries. The Company acknowledges and agrees that (i) the purchase and sale of the Shares pursuant to this Agreement, including the determination of the public offering price of the Shares and any related discounts and commissions, is anarm’s-length commercial transaction between the Company, on the one hand, and the Underwriters, on the other hand, (ii) in connection with the offering contemplated hereby and the process leading to such transaction each Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Company or its shareholders, creditors, employees or any other third party, (iii) no Underwriter has assumed, and will not assume, an advisory or fiduciary responsibility in favor of the Company with respect to the offering contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company on other matters) and no Underwriter has an obligation to the Company with

respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement, (iv) each Underwriter and its Affiliates is engaged in a broad range of transactions that involve interests that differ, or may differ, from those of the Company and shall have no obligation to disclose any information regarding such transactions or interests, and (v) no Underwriter has provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company has consulted its own legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

SECTION 15. GOVERNING LAW AND TIME. THIS AGREEMENT, ANY TRANSACTION CONTEMPLATED HEREUNDER AND ANY CLAIM, CONTROVERSY OR DISPUTE ARISING UNDER OR RELATED TO THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD FOR ITS CONFLICTS OF LAWS PRINCIPLES THAT WOULD RESULT IN THE APPLICATION OF ANY LAW OTHER THAN THE LAWS OF THE STATE OF NEW YORK. EXCEPT AS OTHERWISE SET FORTH HEREIN, SPECIFIED TIMES OF DAY REFER TO NEW YORK CITY TIME.

SECTION 16. Trial by Jury. Each of the Company (on its behalf and, to the extent permitted by applicable law, on behalf of its shareholders and affiliates) and the Underwriters hereby irrevocably waives, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Agreement or the transactions contemplated hereby.

SECTION 17. Consent to Jurisdiction. Each of the parties hereto agrees that any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby shall be instituted in (i) the federal courts of the United States of America located in the City and County of New York, Borough of Manhattan or (ii) the courts of the State of New York located in the City and County of New York, Borough of Manhattan (collectively, the “Specified Courts”), and irrevocably submits to the exclusive jurisdiction (except for proceedings instituted in regard to the enforcement of a judgment of any Specified Court, as to which such jurisdiction isnon-exclusive) of the Specified Courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail to such party’s address set forth above shall be effective service of process for any suit, action or proceeding brought in any Specified Court. Each of the parties hereto irrevocably and unconditionally waives any objection to the laying of venue of any suit, action or proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any Specified Court that any such suit, action or proceeding brought in any Specified Court has been brought in an inconvenient forum.

SECTION 18. General Provisions. This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof. This Agreement may be executed in two or more counterparts, each one of which shall be an original, but all of which together shall constitute one and the same instrument. The exchange of copies of this Agreement and of signature pages by facsimile or other electronic means shall constitute effective execution and delivery of this Agreement by the parties hereto and may be used in lieu of the original signature pages to this Agreement for all purposes. This Agreement may not be amended or modified unless in writing by all of the parties hereto, and no condition herein (express or implied) may be waived unless waived in writing by each party whom the condition is meant to benefit. The Article and Section headings herein are for convenience only and shall not affect the construction hereof.

[Signature Page Follows]

If the foregoing is in accordance with your understanding of our agreement, please sign and return to the Company a counterpart hereof, whereupon this instrument, along with all counterparts, will become a binding agreement among the Underwriters, the Company and the Bank in accordance with its terms.


Very truly yours,

SPIRIT OF TEXAS BANCSHARES, INC.

/s/ Dean O. Bass
By: Dean O. Bass
Name: Chairman and Chief Executive Officer

SPIRIT OF TEXAS BANK, SSB

/s/ Dean O. Bass
By: Dean O. Bass
Name: Chairman and Chief Executive Officer

[Signature Page to Underwriting Agreement – 1 of 2]

CONFIRMED AND ACCEPTED,
as of the date first above written:

STEPHENS INC.

KEEFE, BRUYETTE & WOODS, INC.

Acting individually and as Representatives of the

other Underwriters named in Schedule A hereto

STEPHENS INC.

/s/ Scott Studwell

By:

Name: Scott Studwell

KEEFE, BRUYETTE & WOODS, INC.

/s/ Michael Garea

By:

Name: Michael Garea

[Signature Page to Underwriting Agreement – 2 of 2]

SCHEDULE A


Name of Underwriters	Number of Firm Shares
Stephens Inc.		1,100,000
Keefe, Bruyette & Woods, Inc.		700,000
Piper Jaffray & Co.		100,000
Sandler O’Neill & Partners, L.P.		100,000
Total		2,000,000

Schedule A-1

SCHEDULE B

Issuer-Represented General Free Writing Prospectus

None.

Schedule B-1

SCHEDULE C

SPIRIT OF TEXAS BANCSHARES, INC.

2,000,000 Shares of Common Stock

(no par value per share)

1. The public offering price per share for the Shares, determined as provided in said Section 2, shall be $21.50.

2. The purchase price per share for the Shares to be paid by each Underwriter shall be $20.4250, being an amount equal to the public offering price set forth above less $1.0750 per share; provided that the purchase price per share for any Option Shares purchased upon the exercise of the option described in Section 2(b) shall be reduced by an amount per share equal to any dividends or distributions declared by the Company and payable on the Firm Shares but not payable on the Option Shares.

Schedule C-1

SCHEDULED-1

Company

Spirit of Texas Bank, SSB

FNB Asset Management LLC

Chandler

Chandler Bancorp of Nevada, Inc.

Citizens State Bank

CSB Special Assets, LLC

Schedule D-1

SCHEDULED-2

FNB Asset Management LLC

ScheduleD-2

SCHEDULE E

The following persons and entities shall execute and deliverlock-up agreements in the form of Exhibit A:

Executive Officers

Dean O. Bass

Jerry D. Golemon

David M. McGuire

Jeffrey A. Powell

Board of Directors

Robert S. Beall

Nelda Luce Blair

Allen C. Jones, IV

Thomas Jones, Jr.

Leo T. Metcalf, III

Steven M. Morris

William K. Nix

Akash J. Patel

H. D. Patel

Thomas C. Sooy

Schedule E-1

EXHIBIT A

FORM OFLOCK-UP AGREEMENT

Stephens Inc.

111 Center Street

Little Rock, Arkansas 72201

Keefe, Bruyette & Woods, Inc.

787 Seventh Avenue, 4th Floor

New York, NY 10019

As Representatives of the Underwriters

named in Schedule A of the Underwriting Agreement

Re: Proposed Public Offering of Common Stock by Spirit of Texas Bancshares, Inc.

Ladies and Gentlemen:

The undersigned, a shareholder, executive officer and/or director of Spirit of Texas Bancshares, Inc., a Texas corporation (the “Company”), understands that Stephens Inc. (“Stephens”) and Keefe, Bruyette & Woods, Inc. (“KBW,” together with Stephens, the “Representatives”), as representatives of the several Underwriters (each an “Underwriter,” collectively the “Underwriters”), propose to enter into an Underwriting Agreement (the “Underwriting Agreement”) with the Company providing for the public offering of shares of the Company’s common stock, no par value per share (including any securities convertible into or exercisable for such common stock, the “Common Stock”).

In recognition of the benefit that such an offering will confer upon the undersigned as an executive officer and/or director of the Company, or as a holder of the Company’s Common Stock, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned agrees with each Underwriter to be named in the Underwriting Agreement that, during a period of 90 days from the date of the Underwriting Agreement (the “Lock-Up Period”), the undersigned will not, without the prior written consent of each Representative, directly or indirectly, (i) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of, hypothecate, establish an open “put equivalent position” within the meaning of Rule16a-1(h) under the Securities Exchange Act of 1934, as amended, or otherwise dispose of or transfer any shares of the Company’s Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, whether now owned or hereafter acquired by the undersigned or with respect to which the undersigned has or hereafter acquires the power of disposition, or file or cause to be filed any registration statement under the Securities Act of 1933, as amended, with respect to any of the foregoing, (ii) enter into any swap, hedge or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Common Stock, whether any such swap, hedge or transaction is to be settled by delivery of shares of Common Stock or other securities, in cash or otherwise or (iii) publicly disclose the intention to make any such offer, pledge, sale or disposition, or to enter into any such swap, hedge, transaction or other arrangement.

Notwithstanding the foregoing, the undersigned may transfer the undersigned’s shares of Common Stock (i) as abona fide gift or gifts or by will or intestate succession, provided that the donee or donees agree to be bound in writing by the restrictions set forth herein; (ii) to any trust or family limited

partnership for the direct or indirect benefit of the undersigned or the immediate family of the undersigned, provided that the trustee of the trust or general partner of the family limited partnership, as the case may be, agrees to be bound by the restrictions set forth herein, and provided further that any such transfer shall not involve a disposition for value; (iii) pledged in a bona fide transaction which is outstanding prior to or as of the date hereof to a lender to the undersigned and as disclosed in writing to the Representatives prior to the execution of this agreement; (iv) pursuant to the exercise by the undersigned of stock options that have been granted by the Company prior to, and are outstanding as of, the date of the Underwriting Agreement, where the shares of Common Stock received upon any such exercise are held by the undersigned, individually or as fiduciary, in accordance with the terms of this agreement; (v) to the Company for payment of taxes due and owing as a result of the vesting of restricted share awards that have been granted by the Company prior to the date of the Underwriting Agreement and are disclosed in the General Disclosure Package (as defined in the Underwriting Agreement)¹; or (vi) with the prior written consent of each Representative. For purposes of this agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin.

The undersigned represents and warrants that the undersigned beneficially owns the shares of Common Stock covered by this agreement and that the undersigned now has and, except as contemplated by clauses (i) through [(v)][(vi)] above, for the duration of this agreement will have good and marketable title to the undersigned’s shares of Common Stock, free and clear of all liens, encumbrances, and claims whatsoever, except with respect to any liens, encumbrances and claims that were in existence on the date hereof. The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the undersigned’s Common Stock, except in compliance with this agreement. In furtherance of the foregoing, the Company and its transfer agent are hereby authorized to decline to make any transfer of securities if such transfer would constitute a violation or breach of this agreement.

In addition, the undersigned agrees that, during theLock-Up Period, without the prior written consent of each Representative (which consent may be withheld in its sole discretion): (i) the undersigned will not request, make any demand for or exercise any right with respect to, the registration of any Common Stock or any shares of Common Stock or securities convertible into or exchangeable or exercisable for any shares of Common Stock (“Related Securities”) and (ii) the undersigned waives any and all notice requirements and rights with respect to the registration of any shares of Common Stock or Related Securities pursuant to any agreement, understanding or otherwise to which the undersigned is a party.

The undersigned represents and warrants that the undersigned has full power and authority to enter into this agreement. The undersigned agrees that the provisions of this agreement shall be binding also upon the successors, assigns, heirs and personal representatives of the undersigned.

The undersigned understands that, if the Underwriting Agreement does not become effective on or prior to [ ], 2019, or if the Underwriting Agreement (other than the provisions thereof which survive termination) shall terminate or be terminated prior to payment for and delivery of the shares of Common Stock to be sold thereunder, the undersigned shall be released from all obligations under this agreement.

This agreement shall be governed by and construed in accordance with the laws of the State of New York.

[Signature page follows]

¹	NTD: Thiscarve-out will be included only for those executives that have equity awards vesting during thelock-up period.

The undersigned understands that the Company and the Underwriters are relying upon this agreement in proceeding toward consummation of the offering. The undersigned further understands that this agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors, and assigns.


Very truly yours,

Signature:

Name:

Spirit of Texas Bancshares (STXB) 8-KEntry into a Material Definitive Agreement