Old Second Bancorp (OSBC) director logs RSU grant and tax withholding

Rhea-AI Filing Summary

OLD SECOND BANCORP INC director Edward Bonifas reported a mix of equity compensation activity. On February 17, 2026, he received a grant of 3,121 Restricted Stock Units at a stated price of $0.00 per unit, increasing his direct RSU holdings to 13,672 units.

On February 21, 2026, 3,077 Restricted Stock Units were disposed of at $20.57 per share in a tax-withholding disposition tied to vesting on the third anniversary of the grant, with the vested shares issued and added to his common stock holdings. After these transactions, he directly held 172,254 shares of Old Second Bancorp common stock and 13,672 RSUs, with some shares held outright in his name and some held in a trust.

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).

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^*

BONIFAS EDWARD

(Last) (First) (Middle)

37 S RIVER ST

(Street)

AURORA IL 60507

(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
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
02/21/2026

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
Restricted Stock Units	02/17/2026		A		3,121	A	$0	13,672	D
Restricted Stock Units	02/21/2026		F		3,077(1)	D	$20.57	10,595	D
Old Second Bancorp, Inc. Common Stock								3,077(2)	D
Old Second Bancorp, Inc. Common Stock								172,254(3)	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. Represents shares vested upon the third anniversary of the date of grant previously reported and are now issued and added to the reporting person's common stock holdings outright.

2. These shares are held in Mr. Bonifas' name outright.

3. These shares are held in Mr. Bonifas' name in a Trust.

	/s/ Shirley Cantrell, Attorney-in-Fact	02/25/2026
	** 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.

FAQ

What did Old Second Bancorp (OSBC) director Edward Bonifas report on this Form 4?

Edward Bonifas reported a grant of Restricted Stock Units and a related tax-withholding disposition. He received 3,121 RSUs and had 3,077 RSUs withheld at $20.57 per share when they vested and were issued as common stock.

How many Restricted Stock Units did Edward Bonifas receive from Old Second Bancorp (OSBC)?

He received a grant of 3,121 Restricted Stock Units on February 17, 2026. This grant increased his direct RSU holdings to 13,672 units, representing equity-based compensation that may convert into Old Second Bancorp common stock according to plan terms.

What is the 3,077-share transaction reported by Old Second Bancorp (OSBC) director Bonifas?

The 3,077-share transaction is a tax-withholding disposition of Restricted Stock Units at $20.57 per share on February 21, 2026. The units vested on the grant’s third anniversary, and the vested shares were issued and added to his common stock holdings.

How many Old Second Bancorp (OSBC) shares does Edward Bonifas own after these transactions?

After these transactions, Edward Bonifas directly owned 172,254 shares of Old Second Bancorp common stock and 13,672 Restricted Stock Units. Some common shares are held outright in his name and some are held in a trust structure.

Were Edward Bonifas’s Old Second Bancorp (OSBC) Form 4 transactions open-market buys or sells?

No open-market buys or sells were reported. The filing shows a grant of 3,121 Restricted Stock Units and a 3,077-share tax-withholding disposition related to vesting, rather than discretionary purchases or sales in the open market.