Old Second Bancorp (OSBC) executive awarded 10,562 restricted stock units

Rhea-AI Filing Summary

Campbell Darin Patrick reported acquisition or exercise transactions in this Form 4 filing.

OLD SECOND BANCORP INC disclosed that Darin Patrick Campbell, President of Powersports Lending and a director, received a grant of 10,562 restricted stock units on common stock. After this award, he directly holds 10,562 shares of restricted stock and 274,589 shares of common stock.

The grant is split between 5,281 time-based restricted stock units that vest on the third anniversary of the grant date and 5,281 performance-based restricted stock units. The performance-based units may vest between 0% and 175% of the original award, depending on compensation committee-approved performance metrics, with any vested shares delivered within three to five business days after vesting.

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^*

Campbell Darin Patrick

(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)
	President, Powersports Lending

3. Date of Earliest Transaction (Month/Day/Year)
02/17/2026

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	02/17/2026		A		10,562(1)	A	$0	10,562	D
Old Second Bancorp, Inc. Common Stock								274,589	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. Each restricted stock unit represents a contingent right to receive one share of common stock. The reporting person was granted 10,562 restricted stock units on the date of the grant, 5,281 of which are time-based restricted stock units that vest on the third anniversary of the grant date, and 5,281 of which are performance-based restricted stock units that may vest and convert to shares within a range from 0% to 175% of the underlying performance-based restricted stock units originally awarded, depending on our compensation committee approved performance metrics. Vested shares, if any, will be delivered to the reporting person in 3 to 5 business days from the date of vesting.

	/s/ Shirley Cantrell, Attorney-in-Fact	02/24/2026
	** 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 insider transaction did OSBC report for Darin Patrick Campbell?

OLD SECOND BANCORP INC reported that Darin Patrick Campbell received a grant of 10,562 restricted stock units. These units represent contingent rights to common shares rather than an open-market stock purchase, reflecting equity-based compensation tied to time and performance conditions.

How many restricted stock units did OSBC grant to Darin Patrick Campbell?

OSBC granted 10,562 restricted stock units to Darin Patrick Campbell. Each unit represents a contingent right to receive one share of common stock, subject to vesting terms that include time-based and performance-based conditions set by the company’s compensation committee.

What are the vesting terms of Darin Patrick Campbell’s OSBC restricted stock units?

Of the 10,562 restricted stock units, 5,281 are time-based and vest on the third anniversary of the grant date. The remaining 5,281 are performance-based and may vest from 0% to 175% depending on compensation committee-approved performance metrics.

How are OSBC performance-based restricted stock units for Darin Patrick Campbell determined?

The 5,281 performance-based restricted stock units can vest and convert into shares within a 0% to 175% range of the original award. The exact number of shares delivered depends on performance metrics approved by OLD SECOND BANCORP INC’s compensation committee.

When will vested OSBC restricted stock units be delivered to Darin Patrick Campbell?

Any vested shares from Darin Patrick Campbell’s restricted stock units will be delivered within three to five business days after the vesting date. This timing applies to both time-based and performance-based units once the relevant vesting conditions are satisfied.

How many OSBC shares does Darin Patrick Campbell hold after this Form 4 transaction?

After this transaction, Darin Patrick Campbell directly holds 10,562 shares of restricted stock and 274,589 shares of OLD SECOND BANCORP INC common stock. The restricted stock units convert into shares only upon satisfying the specified vesting conditions.