Old Second Bancorp (OSBC) vice chair gets 253-plan share allocation

Rhea-AI Filing Summary

OLD SECOND BANCORP INC vice chairman Gary S. Collins reported a small internal share allocation and updated his holdings. During the first quarter, 253 shares of Old Second Bancorp, Inc. common stock were allocated to his 401(k) under the Old Second Bancorp, Inc. Salary and Savings Plan, bringing that indirect 401(k) position to 7,058 shares as of March 31, 2026.

Separate from the plan, Collins holds 40,136 common shares directly in a brokerage account and 78,256.085 shares indirectly through IRA accounts, plus 37,312 restricted stock units. The filing reflects routine benefit-plan and ownership reporting rather than open-market buying or selling.

Insider Trade Summary

4 transactions reported

Mixed 4 txns

Insider COLLINS GARY S

Role VICE CHAIRMAN

Type	Security	Shares	Price	Value
Other	Old Second Bancorp, Inc. Common Stock	253	$0.00	--
holding	Old Second Bancorp, Inc. Common Stock	--	--	--
holding	Old Second Bancorp, Inc. Common Stock	--	--	--
holding	Restricted Stock Units	--	--	--

Holdings After Transaction: Old Second Bancorp, Inc. Common Stock — 7,058 shares (Indirect, By 401-K); Old Second Bancorp, Inc. Common Stock — 40,136 shares (Direct); Restricted Stock Units — 37,312 shares (Direct)

Footnotes (1)

1. Of this total, 253 shares were allocated during the first quarter pursuant to the Old Second Bancorp, Inc. Salary and Savings Plan. Information was provided herein by the Plan Trustee as of 3-31-26. These shares are held in the reporting person's name in a brokerage account. Included in this total are 41,000 shares in a ROTH IRA and 37,256.085 in a traditional IRA.

Key Figures

401(k) allocation: 253 shares 401(k) holdings: 7,058 shares Direct brokerage holdings: 40,136 shares +2 more

5 metrics

401(k) allocation 253 shares Allocated in Q1 pursuant to Salary and Savings Plan

401(k) holdings 7,058 shares Old Second Bancorp, Inc. common stock as of March 31, 2026

Direct brokerage holdings 40,136 shares Common stock held directly in brokerage account

IRA holdings 78,256.085 shares Includes 41,000 ROTH IRA and 37,256.085 traditional IRA shares

Restricted stock units 37,312 units RSU holdings reported as of March 31, 2026

Key Terms

Old Second Bancorp, Inc. Salary and Savings Plan, Restricted Stock Units, ROTH IRA, traditional IRA, +1 more

5 terms

Old Second Bancorp, Inc. Salary and Savings Plan financial

"253 shares were allocated during the first quarter pursuant to the Old Second Bancorp, Inc. Salary and Savings Plan."

Restricted Stock Units financial

"Security title listed as Restricted Stock Units with 37,312.0000 total units following the transaction."

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

ROTH IRA financial

"Included in this total are 41,000 shares in a ROTH IRA and 37,256.085 in a traditional IRA."

A Roth IRA is a retirement savings account you fund with money that’s already been taxed, and withdrawals taken in retirement under the account rules are tax-free. It matters to investors because it shifts the tax bill to today instead of retirement, potentially increasing after-tax income later—think of it like paying for a lifetime subscription now so you can use it without extra charges in the future—helpful for long-term tax planning and flexibility.

traditional IRA financial

"Included in this total are 41,000 shares in a ROTH IRA and 37,256.085 in a traditional IRA."

transaction code J financial

"Transaction code J is described as Other acquisition or disposition."

Form 4 Insider Transactions: What Each Field Means →

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

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

COLLINS GARY S

(Last) (First) (Middle)

37 S. RIVER ST.

(Street)

AURORA ILLINOIS 60302

(City) (State) (Zip)

UNITED STATES

(Country)

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)
	VICE CHAIRMAN

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/31/2026

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

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

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

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	03/31/2026		J	V	253	A	$0	7,058(1)	I	By 401-K
Old Second Bancorp, Inc. Common Stock								40,136(2)	D
Old Second Bancorp, Inc. Common Stock								78,256.085(3)	I	IRA
Restricted Stock Units								37,312	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, 253 shares were allocated during the first quarter pursuant to the Old Second Bancorp, Inc. Salary and Savings Plan. Information was provided herein by the Plan Trustee as of 3-31-26.

2. These shares are held in the reporting person's name in a brokerage account.

3. Included in this total are 41,000 shares in a ROTH IRA and 37,256.085 in a traditional IRA.

	/s/ Shirley Cantrell, Attorney-in-Fact	04/02/2026
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider activity did OSBC vice chairman Gary S. Collins report?

Gary S. Collins reported an internal allocation of 253 OSBC shares to his 401(k) under the company’s Salary and Savings Plan, along with updated totals for his direct, IRA, and restricted stock unit holdings as of March 31, 2026.

Were the OSBC shares in this Form 4 bought or sold on the open market?

No open-market trades were reported. The 253 OSBC shares were allocated to Gary S. Collins’ 401(k) through the Old Second Bancorp, Inc. Salary and Savings Plan, which is characterized as an “other” transaction rather than a market purchase or sale.

How many OSBC shares does Gary S. Collins hold directly after this filing?

After this filing, Gary S. Collins holds 40,136 OSBC common shares directly in a brokerage account. This direct position is separate from his 401(k) plan holdings, IRA accounts, and his reported restricted stock units.

What are Gary S. Collins’ OSBC holdings through retirement and savings plans?

Gary S. Collins holds 7,058 OSBC shares indirectly via his 401(k) after a 253-share allocation, and 78,256.085 shares in IRA accounts, including 41,000 shares in a ROTH IRA and 37,256.085 in a traditional IRA.

How many restricted stock units related to OSBC does Gary S. Collins report?

Gary S. Collins reports 37,312 restricted stock units tied to Old Second Bancorp, Inc. These units represent a form of equity-based compensation and are listed separately from his common stock positions in the Form 4 filing.

What does transaction code J mean in this OSBC Form 4 filing?

Transaction code J is described as an “other acquisition or disposition.” In this case, it reflects the allocation of 253 OSBC shares to Gary S. Collins’ 401(k) pursuant to the Old Second Bancorp, Inc. Salary and Savings Plan.