Company: OSBC
Filing Date: 2025-04-23
Form Type: S-4
Source: 0001104659-25-037832
Chunk: 97

Company: OLD SECOND BANCORP INC
Filing Date: 2025-04-23
Form: S-4
Chunk 97
---
orp Financial as of the effective time will generally be recorded at their respective fair values and added to those of Old Second. Any excess of purchase price over the acquisition accounting values will be recorded as goodwill. Consolidated financial statements of Old Second issued after the merger will reflect these acquisition accounting values and will not be restated retroactively to reflect the historical financial position or results of operations of Bancorp Financial.

### PUBLIC TRADING MARKETS
Old Second common stock is listed on NASDAQ under the symbol “OSBC.” Bancorp Financial common stock is not quoted or listed on any securities exchange. Following the merger, shares of Old Second common stock will continue to be traded on NASDAQ.

Under the merger agreement, Old Second will cause the shares of Old Second common stock to be issued in the merger to be approved for listing on NASDAQ, subject to notice of issuance, and the merger agreement provides that neither Old Second nor Bancorp Financial will be required to complete the merger if such shares are not authorized for listing on NASDAQ.

### RESALE OF SHARES OF OLD SECOND COMMON STOCK
All shares of Old Second common stock received by Bancorp Financial stockholders in the merger will be freely tradable for purposes of the Securities Act and the Exchange Act, except for Old Second common stock received by any Bancorp Financial stockholder who becomes an “affiliate” of Old Second after completion of the merger. This proxy statement/prospectus does not cover resales of Old Second common stock received by any person upon completion of the merger, and no person is authorized to make any use of this proxy statement/prospectus in connection with any resale.

<div align='center'>61</div>

TABLE OF CONTENTS

### THE MERGER AGREEMENT
The description of the merger agreement in this section and elsewhere in this proxy statement/prospectus is qualified in its entirety by reference to the complete text of the merger agreement, a copy of which is attached as Annex A and incorporated by reference into this proxy statement/prospectus. This summary may not contain all of the information about the merger agreement that may be important to you. You are urged to read the full text of the merger agreement carefully and in its entirety as it is the legal document governing the merger.

#### Explanatory Note Regarding the Merger Agreement
The merger agreement is included to provide you with information regarding its terms. Neither the merger agreement nor the summary of its material terms included in this section is intended to provide any factual information about Old Second or Bancorp Financial. Factual disclosures about Old Second and