TCBX

Business Context and Reporting Period

This Form 8-K, dated October 22, 2025, reports a material event for Third Coast Bancshares, Inc. (TCBX). The filing announces the execution of a definitive Merger Agreement with Keystone Bancshares, Inc. (Keystone). Under the agreement, Third Coast will acquire Keystone through a multi-step merger process, resulting in Keystone becoming a wholly-owned subsidiary of Third Coast and the subsequent consolidation of their respective banking subsidiaries.

Key Financial Metrics

The filing text does not provide specific financial metrics such as revenue, profit, cash flow, margins, debt, or liquidity figures for either Third Coast or Keystone. This document serves as a notification of the transaction structure and regulatory disclosures rather than a financial performance report. Specific financial data regarding the transaction (e.g., exchange ratio, consideration value) is not detailed in the provided text and is expected to be disclosed in the forthcoming Form S-4 registration statement.

Material Changes and Transaction Structure

• Merger Agreement Execution: On October 22, 2025, Third Coast, its subsidiary Arch Merger Sub, Inc., and Keystone entered into an Agreement and Plan of Reorganization.
• Transaction Steps:
  1. Arch Merger Sub merges with and into Keystone, with Keystone surviving as a Third Coast subsidiary.
  2. Keystone immediately merges with and into Third Coast (Second Step Merger), with Third Coast surviving.
  3. Keystone Bank, SSB merges with and into Third Coast Bank, with Third Coast Bank surviving.
• Shareholder Approval: The transaction is subject to approval by the shareholders of both Third Coast and Keystone.
• Regulatory Approval: Closing is contingent upon receiving required regulatory approvals.

Guidance, Outlook, and Risks

Management Commentary and Outlook: Management has issued forward-looking statements regarding the expected completion date and financial benefits of the transaction. However, the filing explicitly states that actual results may differ materially from these expectations. Third Coast intends to file a Form S-4 containing a joint proxy statement/prospectus with detailed transaction terms.

Material Risks and Contingencies: The filing outlines significant risks that could prevent the transaction from closing or diminish its value, including:

• Failure to obtain required regulatory, shareholder, or other approvals.
• Termination rights under the Merger Agreement.
• Integration challenges, including operational disruptions and higher-than-expected costs.
• Dilution to Third Coast shareholders from the issuance of additional common stock.
• Adverse changes in economic conditions, interest rates, or asset quality.
• Diversion of management attention from ongoing business operations.

Investor Verification Checklist

• Form S-4 Filing: Verify the upcoming Form S-4 registration statement for the definitive exchange ratio, consideration details, and pro forma financial information.
• Shareholder Vote: Confirm the timeline and requirements for shareholder approval meetings for both Third Coast and Keystone.
• Regulatory Status: Monitor the status of regulatory approvals required for the merger of the banking subsidiaries.
• Termination Conditions: Review the specific conditions under which either party may terminate the Merger Agreement.
• Dilution Impact: Assess the potential dilution impact on Third Coast's existing shareholders based on the share issuance terms in the proxy statement.