Byline Bancorp to Acquire Illinois State Bancorp in $87.9 Million Expansion Deal

Key numbers

Deal value	$88M
Share of market cap	5.2%
Share of annual revenue	19.9%

Key highlights

• Total transaction value estimated at $87.9 million based on recent closing prices
• Acquisition includes subsidiaries First Nations Bank and The Bank of Bourbonnais
• Byline adds approximately $510.5 million in total deposits and $470.5 million in loans
• Combined entity will manage approximately $10.5 billion in total assets upon closing
• Consideration involves 1.4 million shares of BY common stock and $28.9 million in cash

What Is the Deal?

Chicago-based Byline Bancorp has reached a definitive agreement to merge with Illinois State Bancorp, Inc. in a transaction structured with both cash and equity. The deal, valued at approximately $87.9 million as of early October 2026, encompasses the target entire banking operations, including First Nations Bank and The Bank of Bourbonnais. Upon the successful completion of the merger, which is projected to close in the first quarter of 2027, the combined organization will operate 48 branches. The transaction aims to consolidate Byline presence in the competitive Chicagoland banking landscape while integrating a stable portfolio of community-focused financial assets.

Deal Structure & Terms

• Issuance of approximately 1.4 million shares of Byline common stock to target shareholders
• Cash consideration totaling $28.9 million paid to Illinois State Bancorp shareholders
• Additional 5.1 million dollar payment allocated for the cancellation of outstanding stock options and warrants
• Transaction pricing determined based on Byline closing stock price of 37.34 on October 5, 2026
• Merger requires customary regulatory approvals and Illinois State Bancorp shareholder consent

Down 1.6% since our story on 6 Oct: $37.34 when we broke it → $36.74 at the close on 13 Oct. Daily closing prices. Source: Yahoo Finance.

Show the prices

14 Sep	$38.43
15 Sep	$38.18
16 Sep	$37.62
17 Sep	$37.61
18 Sep	$37.52
21 Sep	$37.47
22 Sep	$37.00
23 Sep	$36.88
24 Sep	$37.11
25 Sep	$37.44
28 Sep	$37.18
29 Sep	$36.90
30 Sep	$36.83
1 Oct	$37.19
2 Oct	$37.74
5 Oct	$37.63
6 Oct	$37.34
7 Oct	$36.57
8 Oct	$36.88
9 Oct	$36.32
12 Oct	$36.79
13 Oct	$36.74

Strategic Rationale

The acquisition is designed to accelerate Byline objective of becoming the preeminent commercial bank in the Chicago market. By acquiring Illinois State Bancorp, Byline gains a high-quality and complementary franchise that enhances its presence in attractive suburban and urban markets. The deal is specifically intended to add a stable core deposit base and expand customer relationships through relationship-driven commercial and community banking services. Management indicated that the partnership aligns with their commitment to local decision-making and personalized service. Additionally, the move provides further scale to leverage Byline existing investments in technology and innovation across a broader customer base.

Business Overview

Byline Bancorp operates as a regional bank holding company primarily serving the Chicago metropolitan area through its subsidiary, Byline Bank. The firm specializes in commercial banking services, including small business lending and relationship-based community banking. The acquisition target, Illinois State Bancorp, has operated for over 35 years, building a network that includes three branches in the Chicago area and one in Bourbonnais. This integration adds 470.5 million dollars in loans and 510.5 million dollars in deposits to Byline balance sheet, enhancing its core deposit base and providing deeper market density within key Illinois communities.

Financial Context

With a market capitalization of approximately 1.69 billion dollars, Byline is executing this 87.9 million dollar acquisition as part of a sustained expansion strategy. The company reported annual revenue of 441.5 million dollars and maintains a price-to-earnings ratio of 11.25x. This latest move follows the September 2024 acquisition of First Security Bancorp for 41 million dollars, demonstrating a recurring pattern of inorganic growth via regional community bank consolidations. The current deal represents roughly 5.2 percent of Byline total market value and will result in a combined entity holding roughly 8.4 billion dollars in total deposits and 8.0 billion dollars in loans.

Management commentary

“This partnership represents another meaningful step in Byline's growth strategy and further strengthens our position in the Chicago market.”

“We believe this partnership will drive sustainable growth, enhance long-term stockholder value, and reinforce our commitment to the local markets and communities we proudly serve.”

BYLINE BANCORP, INC. · financial snapshot

Share price	$37.34
Market cap	$1.7B
Revenue (annual)	$442M
P/E (TTM)	11.2×
1-month price change	-3.56%
Sector	Financial ServicesBanks - Regional

Reference market data from a third-party provider, as of the story. Not a valuation or a recommendation.