[Form 4] Byline Bancorp, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Ptacin Brogan, Head of Commercial Banking at Byline Bancorp (BY), reported transactions on 08/28/2025. The filing shows an acquisition of 11,812 common shares at $11.65 and a disposition of 11,812 common shares at $29.10 on the same date, leaving 21,774 shares directly owned. An additional 27,200 shares are held indirectly in a revocable trust where Brogan is trustee.

Positive

• Acquisition disclosed: 11,812 common shares acquired at $11.65 on 08/28/2025
• Indirect ownership disclosed: 27,200 shares held in the Brogan M. Ptacin Rev Trust, providing clarity on total beneficial holdings

Negative

• Disposition disclosed: 11,812 common shares sold at $29.10 on 08/28/2025, reducing direct holdings to 21,774 shares
• No explanatory notes: Filing contains no explanation for the same-day equal buy and sell transactions

Insights

Financial Analyst

Insider activity shows simultaneous buy and sell; net direct holdings unchanged materially.

The report documents same-day acquisition and sale of equal share amounts (11,812), with differing reported prices ($11.65 acquisition, $29.10 sale). Direct beneficial ownership after these transactions is 21,774 shares and an additional 27,200 shares are held indirectly via a revocable trust. The transactions are routine Section 16 disclosures and do not by themselves indicate a material change to company control or capital structure.

Corporate Governance Expert

Disclosure is complete for Section 16 purposes; indirect holdings via trust are clearly reported.

The filing properly identifies the reporting person, relationship to issuer, transaction dates, codes, prices and post-transaction ownership, including indirect ownership through the Brogan M. Ptacin Rev Trust dated 3/24/2004. No amendments or additional explanatory notes are provided beyond the signature by an attorney-in-fact.

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^*

Ptacin Brogan

(Last) (First) (Middle)

180 N. LASALLE ST.

SUITE 300

(Street)

CHICAGO IL 60601

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BYLINE BANCORP, INC. [ BY ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	HEAD OF COMMERCIAL BANKING

3. Date of Earliest Transaction (Month/Day/Year)
08/28/2025

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
Common stock	08/28/2025		M		11,812	A	$11.65	33,586	D
Common stock	08/28/2025		S		11,812	D	$29.1	21,774	D
Common stock								27,200	I	By Brogan M. Ptacin Rev Trust Dtd 3/24/2004 Brogan M. Ptacin TTEE

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
Stock Option	$11.65	08/28/2025		M			11,812	05/31/2018	12/15/2025	Common stock	11,812	$0	9,450	D

Explanation of Responses:

	/s/ Thomas J. Bell III, Attorney-in-Fact	08/29/2025
	** 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 transactions did Ptacin Brogan report for BY on 08/28/2025?

Acquired 11,812 common shares at $11.65 and sold 11,812 common shares at $29.10 on 08/28/2025

How many Byline Bancorp (BY) shares does Ptacin Brogan own after the reported transactions?

21,774 shares directly and an additional 27,200 shares indirectly via the Brogan M. Ptacin Rev Trust

What is Ptacin Brogan's role at Byline Bancorp as reported on the Form 4?

Head of Commercial Banking and an officer of the issuer

Were any derivative securities reported by Ptacin Brogan in this filing?

Yes: A stock option with exercise price $11.65 and 11,812 underlying shares is reported, with 9,450 options remaining exercisable and owned directly

Who signed the Form 4 filing for Ptacin Brogan?

Thomas J. Bell III, Attorney-in-Fact, signed the filing on 08/29/2025