Company: OSBC
Filing Date: 2025-05-08
Form Type: 424B3
Source: 0001104659-25-046065
Chunk: 50

Company: OLD SECOND BANCORP INC
Filing Date: 2025-05-08
Form: 424B3
Chunk 50
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By Mail : by completing and returning the accompanying proxy card in the enclosed postage-paid envelope (the envelope requires no additional postage if mailed in the United States.).

If you intend to submit your proxy via the Internet, you must do so by 11:59 p.m., Eastern Time, on the day before the Bancorp Financial special meeting. If you intend to submit your proxy by mail, your completed proxy card must be received before the Bancorp Financial special meeting.

Bancorp Financial requests that holders of Bancorp Financial common stock vote over the Internet or by completing and signing the accompanying proxy card and returning it as soon as possible in the enclosed postage-paid envelope. When the accompanying proxy card is returned properly executed, the shares of Bancorp Financial common stock represented by it will be voted at the Bancorp Financial special meeting in accordance with the instructions contained on the proxy card. If you make no specification on your proxy card as to how you want your shares voted before signing and returning it, your proxy will be voted “FOR” the merger proposal, “FOR” the stockholders agreement amendment proposal, and “FOR” the adjournment proposal.

If a holder’s shares are held in “street name” by a bank, broker or other nominee, the holder should check the voting form used by that firm to determine whether the holder may vote by the Internet.

#### Every vote is important
**. Accordingly, you should sign, date and return the enclosed proxy card, or vote via the Internet, whether or not you plan to attend the Bancorp Financial special meeting.**

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As of the date hereof, the Bancorp Financial board of directors has no knowledge of any business that will be presented for consideration at the Bancorp Financial special meeting and that would be required to be set forth in this proxy statement/prospectus or the related proxy card other than the matters set forth in Bancorp Financial’s Notice of Special Meeting of Stockholders. If any other matter is properly presented at the Bancorp Financial special meeting for consideration, the persons named in the enclosed form of proxy and acting thereunder will vote in accordance with their discretion on such matter.

#### Shares Held in Street Name
If you hold shares of Bancorp Financial common stock through a bank, broker or other nominee, you are considered the “beneficial holder” of the shares held for you in what is known as “street name.” The holder of record of such shares is your bank, broker or other nominee, and not