Byline Bancorp: agrees to acquire Illinois State Bancorp

What happened

• On Oct 6, 2026, Byline Bancorp, Inc. announced the execution of an Agreement and Plan of Merger in connection with its proposed acquisition of Illinois State Bancorp, Inc. and Illinois State Bancorp's wholly owned bank subsidiaries, First Nations Bank and The Bank of Bourbonnais. Byline has also provided supplemental information regarding the proposed transaction.

Key details

• Date of announcement: Oct 6, 2026.
• Target: Illinois State Bancorp, Inc., and its bank subsidiaries First Nations Bank (Illinois chartered) and The Bank of Bourbonnais (Illinois chartered).
• Byline intends to file a registration statement on Form S-4 with the SEC that will include a proxy statement of Illinois State Bancorp and a prospectus of Byline; a definitive proxy statement/prospectus will be sent to Illinois State Bancorp shareholders.
• The filing includes forward-looking statements and refers to risk factors in Byline’s Annual Report on Form 10-K for the year ended Dec 31, 2025 (filed Feb 27, 2026).

Why it may matter

• Item 7.01 (Regulation FD disclosure) was used to announce the merger agreement and supplemental materials. Item 9.01 lists exhibits filed with the report.
• This filing does not show why the insider traded or why the company acted.