Old Second Bancorp (OSBC) vice chair trims stake with 22K-share sale

Rhea-AI Filing Summary

Old Second Bancorp vice chairman Gary S. Collins reported an open-market sale of 22,154 shares of Old Second Bancorp, Inc. Common Stock on March 20, 2026 at a weighted average price of $19.3841 per share, with trades ranging from $19.37 to $19.40.

After this sale, he holds 40,136 shares directly, plus indirect holdings of 78,256.085 shares in IRAs (including 41,000 in a Roth IRA and 37,256.085 in a traditional IRA) and 6,805 shares through a 401(k), along with 37,312 restricted stock units.

Insider Trade Summary

Net Seller: 22,154 shares ($429,435)

Net Sell 4 txns

Insider COLLINS GARY S

Role VICE CHAIRMAN

Sold 22,154 shs ($429K)

Type	Security	Shares	Price	Value
Sale	Old Second Bancorp, Inc. Common Stock	22,154	$19.3841	$429K
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 — 40,136 shares (Direct); Old Second Bancorp, Inc. Common Stock — 78,256.085 shares (Indirect, IRA); Restricted Stock Units — 37,312 shares (Direct)

Footnotes (1)

1. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $19.37 to $19.40, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. Included in this total are 41,000 shares in a ROTH IRA and 37,256.085 in a traditional IRA.

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)
03/20/2026

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	03/20/2026		S		22,154	D	$19.3841(1)	40,136	D
Old Second Bancorp, Inc. Common Stock								78,256.085(2)	I	IRA
Old Second Bancorp, Inc. Common Stock								6,805	I	By 401-K
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. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $19.37 to $19.40, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

2. 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	03/23/2026
	** 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 did OSBC vice chairman Gary S. Collins do in this Form 4 filing?

Gary S. Collins reported selling 22,154 OSBC shares in an open-market transaction. The weighted average sale price was $19.3841 per share, based on multiple trades executed between $19.37 and $19.40 on March 20, 2026.

At what price were the Old Second Bancorp (OSBC) shares sold?

The shares were sold at a weighted average of $19.3841 per share. According to the disclosure, the individual trades occurred in a price range from $19.37 to $19.40, with Collins offering to provide full trade details upon request.

How many Old Second Bancorp (OSBC) shares does Gary S. Collins still hold directly?

Collins now directly holds 40,136 OSBC shares after the reported sale. This direct position is separate from his indirect holdings in retirement accounts and his vested and unvested restricted stock units disclosed in the same report.

What indirect Old Second Bancorp (OSBC) holdings does Gary S. Collins report?

Collins reports 78,256.085 OSBC shares in IRAs, including 41,000 in a Roth IRA and 37,256.085 in a traditional IRA, plus 6,805 shares held through a 401(k) plan, all categorized as indirect ownership.

Does Gary S. Collins hold any Old Second Bancorp restricted stock units (RSUs)?

Yes, Collins reports holding 37,312 restricted stock units of Old Second Bancorp. These RSUs represent additional potential equity, separate from his directly owned shares and indirect holdings in retirement and savings plans.

What is the overall size of Gary S. Collins’ Old Second Bancorp (OSBC) equity position after this sale?

Collins retains a substantial OSBC equity position, including 40,136 directly held shares, 78,256.085 shares in IRAs, 6,805 shares via a 401(k), and 37,312 restricted stock units, as disclosed in the insider report.