Director at Old Second Bancorp (NASDAQ: OSBC) reports small share purchase

Rhea-AI Filing Summary

Old Second Bancorp Inc. director Billy J. Lyons Jr. reported a small open-market purchase of company stock. He bought 24 shares of Old Second Bancorp, Inc. common stock at a price of $20.90 per share, bringing his direct common stock holdings to 20,097 shares. He also reports holding 10,595 Restricted Stock Units.

Insider Trade Summary

Net Buyer: 24 shares ($502)

Net Buy 2 txns

Insider Lyons Billy J Jr.

Role null

Bought 24 shs ($501.60)

Type	Security	Shares	Price	Value
Purchase	Old Second Bancorp, Inc. Common Stock	24	$20.90	$501.60
holding	Restricted Stock Units	--	--	--

Holdings After Transaction: Old Second Bancorp, Inc. Common Stock — 20,097 shares (Direct, null); Restricted Stock Units — 10,595 shares (Direct, null)

Footnotes (1)

Key Figures

Open-market purchase: 24 shares Purchase price: $20.90 per share Common shares held: 20,097 shares +2 more

5 metrics

Open-market purchase 24 shares Old Second Bancorp, Inc. common stock bought by director

Purchase price $20.90 per share Price paid for 24 common shares on transaction date

Common shares held 20,097 shares Direct Old Second Bancorp, Inc. common stock after transaction

Restricted Stock Units held 10,595 units RSUs reported as of transaction date

Net buy shares 24 shares Net buy-sell activity in this Form 4 period

Key Terms

Restricted Stock Units, open-market purchase, Form 4

3 terms

Restricted Stock Units financial

"The filing reports 10,595 Restricted Stock Units held by the director."

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.

open-market purchase financial

"The 24 common shares were reported as an open-market purchase."

An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.

Form 4 regulatory

"This insider trading activity was disclosed in a Form 4 filing."

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

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^*

Lyons Billy J Jr.

(Last) (First) (Middle)

37 SOUTH RIVER STREET

(Street)

AURORA ILLINOIS 60507

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/11/2026

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	05/11/2026		P		24	A	$20.9	20,097	D
Restricted Stock Units								10,595	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:

	/s/ Shirley Cantrell, Attorney-in-Fact	05/12/2026
	** 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 transaction did OSBC director Billy J. Lyons Jr. report?

Billy J. Lyons Jr. reported buying 24 OSBC shares in an open-market purchase at $20.90 per share. This Form 4 filing also shows his updated direct ownership and his separate holdings of Restricted Stock Units in Old Second Bancorp Inc.

How many Old Second Bancorp (OSBC) shares does Billy J. Lyons Jr. now hold?

After the reported trade, Lyons holds 20,097 OSBC common shares directly. The Form 4 also discloses that he holds 10,595 Restricted Stock Units, which are a form of stock-based compensation subject to vesting or other conditions.

What price did OSBC director Billy J. Lyons Jr. pay for the new shares?

Lyons paid $20.90 per share for 24 Old Second Bancorp, Inc. common shares in an open-market purchase. This transaction was reported as a direct ownership change in his Form 4 insider trading report filed with the SEC.

What are the Restricted Stock Units reported by OSBC director Lyons?

The filing shows Lyons holds 10,595 Restricted Stock Units. Restricted Stock Units are a form of equity compensation that typically convert into company shares over time, subject to vesting schedules and other conditions defined in the company’s compensation plans.

Is the OSBC Form 4 transaction a buy or sell by the director?

The Form 4 reflects a net-buy transaction. Lyons completed an open-market purchase of 24 Old Second Bancorp, Inc. common shares, with no reported sales. The summary of activity shows net buying of 24 shares for this reporting period.