BY

SEC source: 0000913849-18-000027 · form4_020118.xml · derivative · entry 6

Meyer Donald J · CIK 0001396123 · EVP OF COMM. BANKING

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,748

Underlying: Common Stock · 22,902 shares

Expires 2025-03-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: The options exercised were vested and currently exercisable.

SEC source: 0000913849-18-000027 · form4_020118.xml · nonDerivative · entry 4

Meyer Donald J · CIK 0001396123 · EVP OF COMM. BANKING

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,000

F2 · price: Price reflects the weighted average sale price for the shares, which were sold in multiple transactions at prices that ranged from $22.31 to $22.66. Upon request of the SEC staff, the issuer or a security holder of the issuer, the reporting person will provide information regarding the number of shares sold at each separate price.

SEC source: 0000913849-18-000027 · form4_020118.xml · nonDerivative · entry 3

Meyer Donald J · CIK 0001396123 · EVP OF COMM. BANKING

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,902

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000913849-18-000027 · form4_020118.xml · derivative · entry 5

Meyer Donald J · CIK 0001396123 · EVP OF COMM. BANKING

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 41,650

Underlying: Common Stock · 7,098 shares

Expires 2025-03-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: The options exercised were vested and currently exercisable.

SEC source: 0000913849-18-000027 · form4_020118.xml · nonDerivative · entry 2

Meyer Donald J · CIK 0001396123 · EVP OF COMM. BANKING

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,000

F1 · price: Price reflects the weighted average sale price for the shares, which were sold in multiple transactions at prices that ranged from $22.26 to $22.42. Upon request of the SEC staff, the issuer or a security holder of the issuer, the reporting person will provide information regarding the number of shares sold at each separate price.

SEC source: 0000913849-18-000027 · form4_020118.xml · nonDerivative · entry 1

Meyer Donald J · CIK 0001396123 · EVP OF COMM. BANKING

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,098

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000913849-18-000095 · form5_021318.xml · derivative · entry 1

LAMMERS BRUCE W · CIK 0001169102 · EVP & President of SBC

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,600

Underlying: Common Stock · 45,600 shares

Expires 2026-10-14

F1 · shares: Reflects performance vesting of stock options awarded to the reporting person on October 14, 2016.

SEC source: 0000913849-18-000043 · form4_020518.xml · derivative · entry 4

Meyer Donald J · CIK 0001396123 · EVP OF COMM. BANKING

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,374

Underlying: Common Stock · 24,374 shares

Expires 2025-03-02

F3 · shares: Reflects performance vesting of a stock option grant awarded to the reporting person on March 2, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer

F3 · derivative.exercise_date: Reflects performance vesting of a stock option grant awarded to the reporting person on March 2, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer

SEC source: 0000913849-18-000043 · form4_020518.xml · derivative · entry 3

Meyer Donald J · CIK 0001396123 · EVP OF COMM. BANKING

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,374

Underlying: Common Stock · 8,126 shares

Expires 2025-03-02

F2 · shares: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on March 2, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F2 · derivative.exercise_date: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on March 2, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000099 · form5_021218.xml · derivative · entry 2

Bell Thomas J III · CIK 0001451652 · SVP and Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,624

Underlying: Common Stock · 14,624 shares

Expires 2025-06-26

F2 · shares: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F2 · derivative.exercise_date: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000099 · form5_021218.xml · derivative · entry 1

Bell Thomas J III · CIK 0001451652 · SVP and Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,624

Underlying: Common Stock · 4,875 shares

Expires 2025-06-26

F1 · shares: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F1 · derivative.exercise_date: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000098 · form5_021218.xml · derivative · entry 2

Corby Lindsay Y · CIK 0001557298 · EVP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,374

Underlying: Common Stock · 24,374 shares

Expires 2025-06-26

F2 · shares: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F2 · derivative.exercise_date: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000098 · form5_021218.xml · derivative · entry 1

Corby Lindsay Y · CIK 0001557298 · EVP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,374

Underlying: Common Stock · 8,126 shares

Expires 2025-06-26

F1 · shares: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F1 · derivative.exercise_date: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000097 · form5_021218.xml · derivative · entry 2

HADRO TIMOTHY C. · CIK 0001709986 · EVP and Chief Credit Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,374

Underlying: Common Stock · 24,374 shares

Expires 2025-03-02

F2 · shares: Reflects performance vesting of a stock option grant awarded to the reporting person on March 2, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F2 · derivative.exercise_date: Reflects performance vesting of a stock option grant awarded to the reporting person on March 2, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000097 · form5_021218.xml · derivative · entry 1

HADRO TIMOTHY C. · CIK 0001709986 · EVP and Chief Credit Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,374

Underlying: Common Stock · 8,126 shares

Expires 2025-03-02

F1 · shares: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on March 2, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F1 · derivative.exercise_date: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on March 2, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000096 · form5_021218.xml · derivative · entry 2

HERENCIA ROBERTO R · CIK 0001214993 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 107,247

Underlying: Common Stock · 107,247 shares

Expires 2025-06-26

F2 · shares: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F2 · derivative.exercise_date: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000096 · form5_021218.xml · derivative · entry 1

HERENCIA ROBERTO R · CIK 0001214993 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 107,247

Underlying: Common Stock · 35,753 shares

Expires 2025-06-26

F1 · shares: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F1 · derivative.exercise_date: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000094 · form5_021218.xml · derivative · entry 2

Paracchini Alberto J · CIK 0001482596 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 107,247

Underlying: Common Stock · 107,247 shares

Expires 2025-06-26

F2 · shares: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F2 · derivative.exercise_date: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000094 · form5_021218.xml · derivative · entry 1

Paracchini Alberto J · CIK 0001482596 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 107,247

Underlying: Common Stock · 35,753 shares

Expires 2025-06-26

F1 · shares: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F1 · derivative.exercise_date: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000093 · form5_021218.xml · derivative · entry 2

SCHOBERT RICHARD · CIK 0001709992 · Chief Risk Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,749

Underlying: Common Stock · 9,749 shares

Expires 2025-06-26

F2 · shares: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F2 · derivative.exercise_date: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000093 · form5_021218.xml · derivative · entry 1

SCHOBERT RICHARD · CIK 0001709992 · Chief Risk Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,749

Underlying: Common Stock · 3,250 shares

Expires 2025-06-26

F1 · shares: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F1 · derivative.exercise_date: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000092 · form5_021218.xml · derivative · entry 2

BIGGAM MEGAN · CIK 0001709994 · SVP of Retail Banking

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,187

Underlying: Common Stock · 12,187 shares

Expires 2025-06-26

F2 · shares: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F2 · derivative.exercise_date: Reflects performance vesting of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000913849-18-000092 · form5_021218.xml · derivative · entry 1

BIGGAM MEGAN · CIK 0001709994 · SVP of Retail Banking

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,187

Underlying: Common Stock · 4,063 shares

Expires 2025-06-26

F1 · shares: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

F1 · derivative.exercise_date: Reflects the performance vesting of the remaining unvested portion of a stock option grant awarded to the reporting person on June 26, 2015. 20% of these earned options remain subject to time vesting and will vest on June 28, 2018, subject to continued service with the issuer.

SEC source: 0000899243-17-018033 · doc4.xml · nonDerivative · entry 2

Corby Lindsay Y · CIK 0001557298 · EVP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 16,771

F2 · shares: Represents restricted shares of Common Stock that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

F2 · price: Represents restricted shares of Common Stock that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

SEC source: 0000899243-17-018033 · doc4.xml · nonDerivative · entry 1

Corby Lindsay Y · CIK 0001557298 · EVP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,271

F1 · shares: Represents shares of common stock, par value $0.01 per share ("Common Stock"), of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

F1 · price: Represents shares of common stock, par value $0.01 per share ("Common Stock"), of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

SEC source: 0000899243-17-018032 · doc4.xml · nonDerivative · entry 2

Paracchini Alberto J · CIK 0001482596 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 33,814

F2 · shares: Represents restricted shares of Common Stock that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

F2 · price: Represents restricted shares of Common Stock that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

SEC source: 0000899243-17-018032 · doc4.xml · nonDerivative · entry 1

Paracchini Alberto J · CIK 0001482596 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,814

F1 · shares: Represents shares of common stock, par value $0.01 per share ("Common Stock"), of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

F1 · price: Represents shares of common stock, par value $0.01 per share ("Common Stock"), of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

SEC source: 0000899243-17-018031 · doc4.xml · nonDerivative · entry 3

HERENCIA ROBERTO R · CIK 0001214993 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 103,935

F3 · shares: Represents shares of Common Stock of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

F3 · price: Represents shares of Common Stock of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

SEC source: 0000899243-17-018030 · doc4.xml · nonDerivative · entry 1

BIGGAM MEGAN · CIK 0001709994 · SVP of Retail Banking

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,923

F1 · shares: Represents restricted shares of common stock, par value $0.01 per share, that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

F1 · price: Represents restricted shares of common stock, par value $0.01 per share, that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

SEC source: 0000899243-17-018024 · doc4.xml · nonDerivative · entry 2

CABRERA PHILLIP R. · CIK 0001709906 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,101

F3 · shares: Represents shares of Common Stock purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

F3 · price: Represents shares of Common Stock purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

SEC source: 0000899243-17-018025 · doc4.xml · nonDerivative · entry 2

Bell Thomas J III · CIK 0001451652 · SVP and Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,905

F2 · shares: Represents restricted shares of Common Stock that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

F2 · price: Represents restricted shares of Common Stock that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

SEC source: 0000899243-17-018025 · doc4.xml · nonDerivative · entry 1

Bell Thomas J III · CIK 0001451652 · SVP and Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,905

F1 · shares: Represents shares of common stock, par value $0.01 per share ("Common Stock"), of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

F1 · price: Represents shares of common stock, par value $0.01 per share ("Common Stock"), of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

SEC source: 0000899243-17-018022 · doc4.xml · nonDerivative · entry 1

Meyer Donald J · CIK 0001396123 · EVP of Comm. Banking

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,000

F1 · shares: Represents restricted shares of common stock, par value $0.01 per share, that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

F1 · price: Represents restricted shares of common stock, par value $0.01 per share, that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

SEC source: 0000899243-17-018023 · doc4.xml · nonDerivative · entry 1

SCHOBERT RICHARD · CIK 0001709992 · Chief Risk Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 250

F1 · shares: Represents shares of common stock, par value $0.01 per share ("Common Stock"), of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

F1 · price: Represents shares of common stock, par value $0.01 per share ("Common Stock"), of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017.

SEC source: 0000899243-17-018021 · doc4.xml · nonDerivative · entry 1

HADRO TIMOTHY C. · CIK 0001709986 · EVP and Chief Credit Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,000

F1 · shares: Represents restricted shares of common stock, par value $0.01 per share, that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

F1 · price: Represents restricted shares of common stock, par value $0.01 per share, that will cliff vest on July 6, 2020 subject to continued employment with the issuer.

SEC source: 0000899243-17-018024 · doc4.xml · nonDerivative · entry 1

CABRERA PHILLIP R. · CIK 0001709906 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Phillip R. Cabrera Revocable Trust

Disclosed balance after: 1,600

F1 · shares: Represents shares of common stock of the issuer's predecessor, Byline Bancorp, Inc., an Illinois corporation ("Byline Illinois") purchased by the Phillip R. Cabrera Revocable Trust from another stockholder in a private transaction prior to Byline Illinois's reincorporation in Delaware on June 16, 2017 by way of merger with the issuer. The number of shares of common stock, par value $0.01 per share ("Common Stock"), purchased and the price per share of Common Stock are presented after giving effect to the exchange ratio in the reincorporation merger of one share of the issuer's Common Stock for every five shares of Byline Illinois common stock held by each holder, subject to a cash payment in lieu of fractional shares.

F1 · price: Represents shares of common stock of the issuer's predecessor, Byline Bancorp, Inc., an Illinois corporation ("Byline Illinois") purchased by the Phillip R. Cabrera Revocable Trust from another stockholder in a private transaction prior to Byline Illinois's reincorporation in Delaware on June 16, 2017 by way of merger with the issuer. The number of shares of common stock, par value $0.01 per share ("Common Stock"), purchased and the price per share of Common Stock are presented after giving effect to the exchange ratio in the reincorporation merger of one share of the issuer's Common Stock for every five shares of Byline Illinois common stock held by each holder, subject to a cash payment in lieu of fractional shares.

F2 · ownership.nature: Shares of Common Stock are held through the Phillip R. Cabrera Revocable Trust. Mr. Cabrera possesses the voting and investment power with respect to the shares of Common Stock held by the Philip R. Cabrera Revocable Trust.

SEC source: 0000899243-17-018031 · doc4.xml · nonDerivative · entry 2

HERENCIA ROBERTO R · CIK 0001214993 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Roberto Herencia Inc. Defined Benefit Plan

Disclosed balance after: 10,147

F1 · shares: Represents shares of common stock of the issuer's predecessor, Byline Bancorp, Inc., an Illinois corporation ("Byline Illinois") purchased by Mr. Herencia from another stockholder in a private transaction prior to Byline Illinois's reincorporation in Delaware on June 16, 2017 by way of merger with the issuer. The number of shares of common stock, par value $0.01 per share ("Common Stock"), purchased and the price per share of Common Stock are presented after giving effect to the exchange ratio in the reincorporation merger of one share of the issuer's Common Stock for every five shares of Byline Illinois common stock held by each holder, subject to a cash payment in lieu of fractional shares.

F1 · price: Represents shares of common stock of the issuer's predecessor, Byline Bancorp, Inc., an Illinois corporation ("Byline Illinois") purchased by Mr. Herencia from another stockholder in a private transaction prior to Byline Illinois's reincorporation in Delaware on June 16, 2017 by way of merger with the issuer. The number of shares of common stock, par value $0.01 per share ("Common Stock"), purchased and the price per share of Common Stock are presented after giving effect to the exchange ratio in the reincorporation merger of one share of the issuer's Common Stock for every five shares of Byline Illinois common stock held by each holder, subject to a cash payment in lieu of fractional shares.

F2 · ownership.nature: Shares of Common Stock are held through the Roberto Herencia Inc. Defined Benefit Plan. Mr Herencia possesses the voting and investment power with respect to the shares of Common Stock held by the Roberto Herencia Inc. Defined Benefit Plan.

SEC source: 0000899243-17-018031 · doc4.xml · nonDerivative · entry 1

HERENCIA ROBERTO R · CIK 0001214993 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 81,435

F1 · shares: Represents shares of common stock of the issuer's predecessor, Byline Bancorp, Inc., an Illinois corporation ("Byline Illinois") purchased by Mr. Herencia from another stockholder in a private transaction prior to Byline Illinois's reincorporation in Delaware on June 16, 2017 by way of merger with the issuer. The number of shares of common stock, par value $0.01 per share ("Common Stock"), purchased and the price per share of Common Stock are presented after giving effect to the exchange ratio in the reincorporation merger of one share of the issuer's Common Stock for every five shares of Byline Illinois common stock held by each holder, subject to a cash payment in lieu of fractional shares.

F1 · price: Represents shares of common stock of the issuer's predecessor, Byline Bancorp, Inc., an Illinois corporation ("Byline Illinois") purchased by Mr. Herencia from another stockholder in a private transaction prior to Byline Illinois's reincorporation in Delaware on June 16, 2017 by way of merger with the issuer. The number of shares of common stock, par value $0.01 per share ("Common Stock"), purchased and the price per share of Common Stock are presented after giving effect to the exchange ratio in the reincorporation merger of one share of the issuer's Common Stock for every five shares of Byline Illinois common stock held by each holder, subject to a cash payment in lieu of fractional shares.