[Form 4] OLD SECOND BANCORP INC Insider Trading Activity

Rhea-AI Filing Summary

James Eccher, Chairman & CEO and a director of Old Second Bancorp, Inc. (OSBC), reported transactions on 09/30/2025 on Form 4. The filing shows allocations of 22 shares to his profit sharing account and 134 shares to his employee salary and savings (401(k)) plan, each reported as acquisitions at $0. The report also discloses 329,896 shares of Common Stock held directly and 184,318 Restricted Stock Units held directly. The filer notes that of the direct common shares, 148 are held jointly with spouse and 329,748 are held in a brokerage account. The form is signed by an attorney-in-fact on 10/01/2025.

Positive

• Routine plan allocations (22 shares to profit sharing and 134 shares to 401(k)) show continued participation in company benefit plans
• Substantial insider ownership disclosed: 329,896 common shares and 184,318 restricted stock units, indicating material alignment with shareholders

Negative

• No material negative items such as open-market sales, option exercises, or derivative dispositions are reported

Insights

Securities Analyst

TL;DR: Insider made small plan allocations; significant existing direct equity and RSU holdings remain disclosed.

The Form 4 reports routine plan allocations totaling 156 shares credited to Mr. Eccher's employee plans on 09/30/2025, recorded at $0, consistent with plan distributions or contributions rather than market purchases. The filing separately lists substantial existing holdings: 329,896 shares of common stock held directly and 184,318 restricted stock units. These balances quantify the insider's vested and unvested exposure to OSBC equity and are relevant for assessing insider alignment with shareholders. No derivative transactions or market sales are reported.

Corporate Governance Expert

TL;DR: Disclosure appears routine and complete for the reported allocations; ownership detail includes joint and brokerage holdings.

The Form 4 disclosures identify Mr. Eccher as both chairman/CEO and director and properly attribute allocations to the profit sharing and 401(k) plans with trustee-provided information. The filing distinguishes direct ownership and restricted stock units and clarifies 148 shares are jointly held with spouse and 329,748 are in a brokerage account. Signature by an attorney-in-fact is provided. The report contains no material changes such as large open-market trades, option exercises, or derivative activity.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Eccher James

(Last) (First) (Middle)

37 S. RIVER ST.

(Street)

AURORA IL 60506

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
OLD SECOND BANCORP INC [ OSBC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHAIRMAN AND CEO

3. Date of Earliest Transaction (Month/Day/Year)
09/30/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Old Second Bancorp, Inc. Common Stock	09/30/2025		J	V	22	A	$0	6,311(1)	I	By Profit Sharing
Old Second Bancorp, Inc. Common Stock	09/30/2025		J	V	134	A	$0	32,893(2)	I	By 401-K
Old Second Bancorp, Inc. Common Stock								329,896(3)	D
Restricted Stock Units								184,318	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Of this total, 22 shares were allocated during the third quarter pursuant to the Old Second Bancorp, Inc. Employee Profit Sharing Plan and Trust. Information herein was provided by the plan trustee as of 09-30-25.

2. Of this total are 134 shares that were allocated during the third quarter pursuant to the Old Second Bancorp, Inc. Employee Salary and Savings Plan. Information herein was provided by the plan trustee as of 09-30-25.

3. Included in this total are 148 shares held jointly with spouse and 329,748 shares held in a brokerage account.

	/s/ Shirley Cantrell, Attorney-in-Fact	10/01/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

Who filed the Form 4 for OSBC and what is their role?

The Form 4 was filed for James Eccher, identified as Chairman and CEO and a director of Old Second Bancorp, Inc.

What transactions were reported on the 09/30/2025 Form 4 for OSBC?

The filing reports allocations of 22 shares to a profit sharing plan and 134 shares to a 401(k)/salary and savings plan, both dated 09/30/2025 and reported as acquisitions at $0.

How many OSBC shares and RSUs does the reporting person hold according to the Form 4?

The Form 4 discloses 329,896 shares of common stock held directly and 184,318 restricted stock units held directly.

Are any derivative or option transactions reported in this Form 4?

No. Table II for derivative securities contains no reported transactions in this filing.

Does the filing explain the composition of the direct share holdings?

Yes. The filing states 148 shares are held jointly with spouse and 329,748 shares are held in a brokerage account as part of the 329,896 total.