Company: OSBC
Filing Date: 2025-05-08
Form Type: 424B3
Source: 0001104659-25-046065
Chunk: 137

Company: OLD SECOND BANCORP INC
Filing Date: 2025-05-08
Form: 424B3
Chunk 137
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. Shares of Old Second common stock are not convertible into shares of any other class of capital stock.

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TABLE OF CONTENTS

#### Preferred Stock
Old Second may issue up to 300,000 shares of preferred stock, $1.00 par value per share, from time to time in one or more series. The Old Second board of directors, without further approval of Old Second stockholders, has the authority to fix the dividend rights and terms, conversion rights, voting rights, redemption rights and terms, liquidation preferences, sinking funds and any other rights, preferences, privileges and restrictions applicable to each series of preferred stock. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, adversely affect the voting power of the holders of Old Second common stock.

The authorization of preferred stock could have the effect of impeding the acquisition of control of Old Second by means of a tender offer, a proxy fight, open-market purchases or otherwise in a transaction not approved by our board of directors. See “— Antitakeover Provisions — Charter; Bylaws.”

As of March 31, 2025, Old Second had no shares of preferred stock issued and outstanding.

#### Anti-Takeover Provisions

#### General.
Certain provisions of the Old Second charter, the Old Second bylaws and the DGCL may have the effect of impeding the acquisition of control of Old Second by means of a tender offer, a proxy fight, open-market purchases or otherwise in a transaction not approved by the Old Second board of directors. These provisions may have the effect of discouraging a future takeover attempt which is not approved by the Old Second board of directors but which individual stockholders may deem to be in their best interests or in which Old Second stockholders may receive a substantial premium for their shares over then-current market prices. As a result, stockholders who might desire to participate in such a transaction may not have an opportunity to do so. Such provisions will also render the removal of the current Old Second board of directors or management more difficult.

#### Charter; Bylaws.
These provisions of the Old Second charter and the Old Second bylaws include the following:

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The Old Second board of directors may issue additional authorized shares of Old Second capital stock to deter future attempts to gain control of Old Second, and has the authority to determine the terms of any one or more series of preferred stock, such as voting rights, conversion rates and liquidation preferences. As