Old Second Bancorp (NASDAQ: OSBC) grants 8,858 RSUs to vice chair

Rhea-AI Filing Summary

Old Second Bancorp vice chairman Gary S. Collins reported equity compensation changes and related tax withholding. On February 17, 2026, he received a grant of 8,858 restricted stock units, each representing a right to one share of common stock. Half of these RSUs are time-based and vest on the third anniversary of the grant date, while the other half are performance-based and may ultimately vest between 0% and 175% of the original award, depending on compensation committee–approved performance metrics.

On February 21, 2026, the issuer withheld 2,784 shares at $20.57 per share to cover tax obligations upon vesting of 8,246 previously reported time-based RSUs, with the remaining vested shares added to Collins’s common stock holdings. The filing also updates his direct and indirect ownership positions, including shares held outright, in a brokerage account, IRAs, and a 401(k).

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

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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^*

COLLINS GARY S

(Last) (First) (Middle)

37 S. RIVER ST.

(Street)

AURORA IL 60302

(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)
	VICE CHAIRMAN

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 Units	02/17/2026		A		8,858(1)	A	$0	53,804	D
Restricted Stock Units	02/21/2026		F		2,784(2)	D	$20.57	45,558	D
Old Second Bancorp, Inc. Common Stock								5,462(3)	D
Old Second Bancorp, Inc. Common Stock								46,624(4)	D
Old Second Bancorp, Inc. Common Stock								78,256.085(5)	I	IRA
Old Second Bancorp, Inc. Common Stock								6,805	I	By 401-K

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 8,858 restricted stock units on the date of the grant, 4,429 of which are time-based restricted stock units that vest on the third anniversary of the grant date, and 4,429 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.

2. Represents shares withheld by the issuer to satisfy applicable tax withholding obligations in connection with the vesting of 8,246 previously reported time-based restricted stock units, the remaining shares of which were issued and added to the reporting person's common stock holdings.

3. These shares are held in Mr. Collin's name outright.

4. These shares are held in Mr. Collin's name in a brokerage account.

5. 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	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).
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FAQ

What equity award did OSBC vice chairman Gary Collins receive on February 17, 2026?

Gary Collins received a grant of 8,858 restricted stock units on February 17, 2026. Half are time-based RSUs vesting on the third anniversary, and half are performance-based RSUs that can vest between 0% and 175% of the original award, depending on performance metrics.

How are the Old Second Bancorp performance-based RSUs for OSBC’s vice chairman structured?

The performance-based RSUs can vest between 0% and 175% of the 4,429 units granted. Actual vesting depends on compensation committee–approved performance metrics, and any vested shares will be delivered within 3 to 5 business days after vesting occurs.

Why were 2,784 OSBC shares withheld in the February 21, 2026 Form 4?

The issuer withheld 2,784 shares on February 21, 2026 to satisfy tax withholding obligations. These shares related to the vesting of 8,246 previously reported time-based RSUs; the remaining vested shares were issued and added to Gary Collins’s common stock holdings.

Was the 2,784-share Form 4 transaction for OSBC an open-market sale?

No. The 2,784 shares were withheld by Old Second Bancorp at $20.57 per share to cover taxes on vested RSUs. This is a tax-withholding disposition, not an open-market sale by Gary Collins on a securities exchange.

How quickly will Gary Collins receive shares once his OSBC RSUs vest?

For both time-based and performance-based RSUs, any vested shares will be delivered to Gary Collins within 3 to 5 business days after the vesting date, according to the terms described in the Form 4 footnotes.

How are Gary Collins’s OSBC shares held according to the Form 4?

The filing notes that some shares are held in Gary Collins’s name outright and some in a brokerage account. Additional shares are held indirectly in ROTH and traditional IRAs and a 401(k), with totals for each type of account disclosed.