# EDGAR Filing Document

**Accession Number:** 0000357173
**File Stem:** 0000357173-26-000030
**Filing Date:** 2026-6
**Character Count:** 5203
**Document Hash:** c891c0e17fe622b37941dac262698f0c
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000357173-26-000030.hdr.sgml**: 20260625

**ACCESSION NUMBER**: 0000357173-26-000030

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 12

**CONFORMED PERIOD OF REPORT**: 20260625

**ITEM INFORMATION**: Other Events

**FILED AS OF DATE**: 20260625

**DATE AS OF CHANGE**: 20260625

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** OLD SECOND BANCORP INC
- **CENTRAL INDEX KEY:** 0000357173
- **STANDARD INDUSTRIAL CLASSIFICATION:** STATE COMMERCIAL BANKS [6022]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 363143493
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-10537
- **FILM NUMBER:** 261118719

**BUSINESS ADDRESS:**
- **STREET 1:** 37 S RIVER ST
- **CITY:** AURORA
- **STATE:** IL
- **ZIP:** 60507
- **BUSINESS PHONE:** 6308920202

**MAIL ADDRESS:**
- **STREET 1:** 37 SOUTH RIVER STREET
- **CITY:** AURORA
- **STATE:** IL
- **ZIP:** 60507

?xml version='1.0' encoding='ASCII'? OLD SECOND BANCORP INC_June 25, 2026

I

**United States**

**Securities And Exchange Commission**

**Washington, D.C. 20549**

**FORM 8-K**

**Current Report**

#### Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): **June 25, 2026**

![Graphic](osbc-20260625x8k001.jpg)

(Exact name of registrant as specified in its charter)

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| | | |
|:---|:---|:---|
| &nbsp;&nbsp;**Delaware** | &nbsp;&nbsp;**000-10537** | &nbsp;&nbsp;**36-3143493** |
| &nbsp;&nbsp;(State or other jurisdiction of incorporation) | &nbsp;&nbsp;(Commission File Number) | &nbsp;&nbsp;(I.R.S. Employer Identification No.) |

---

**37 South River StreetAurora, Illinois 60507**(Address of principal executive offices) (Zip code)

#### (630) 892-0202 (Registrant's telephone number, including area code)
**N/A**

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (*see* General Instruction A.2. below):

**☐** Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

**☐** Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

**☐** Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

**☐** Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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| | | |
|:---|:---|:---|
| **Title of each class** | **Trading Symbol(s)** | **Name of each exchange on which registered** |
| Common Stock | OSBC | The Nasdaq Stock Market |

---

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 under the Securities Act (17 CFR 230.405) or Rule 12b-2 under the Exchange Act (17 CFR 240.12b-2).

Emerging growth company **☐**

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. **☐**

------

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| | |
|:---|:---|
| **Item 8.01** | **Other Events.** |

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The Board of Directors of Old Second Bancorp, Inc. (the "Company") has authorized a new share repurchase program under which the Company may repurchase up to $61.2 million of additional shares of the Company's common stock from July 1, 2026 through June 30, 2027 (the "Repurchase Program"). The Company has received nonobjection from the Federal Reserve Bank of Chicago to the Repurchase Program.

Repurchases by the Company under the Repurchase Program may be made from time to time through open market purchases, trading plans established in accordance with U.S. Securities and Exchange Commission rules, privately negotiated transactions, or by other means. The actual means and timing of any repurchases, quantity of purchased shares and prices will be, subject to certain limitations, at the discretion of management and will depend on a number of factors, including, without limitation, market prices of the Company's common stock, general market and economic conditions, and applicable legal and regulatory requirements. Repurchases under the Repurchase Program may be initiated, discontinued, suspended or restarted at any time. The Company is not obligated to repurchase any shares under the Repurchase Program.

The Company's existing share repurchase plan is scheduled to expire on June 30, 2026.

**Signature**

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | |
|:---|:---|:---|
|  | **OLD SECOND BANCORP, INC.** | **OLD SECOND BANCORP, INC.** |
| Dated: June 25, 2026 | By: | /s/ Bradley S. Adams |
|  |  | Bradley S. Adams |
|  |  | Executive Vice President, |
|  |  | Chief Operating Officer, and |
|  |  | Chief Financial Officer |

---