KRYS · Krystal Biotech, Inc.

The transaction was executed in multiple trades ranging from $330 to $330.99. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $327 to $327.99. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

Represents a bona fide gift of Krystal Biotech, Inc.'s Common Stock to a charitable donor-advised fund.

The transaction was executed in multiple trades ranging from $331.02 to $331.99. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $328.01 to $328.99. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $326.04 to $326.98. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $325 to $325.96. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $329.01 to $329.99. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The acquisition and sale of shares of the Company's common stock reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 23, 2026. All transactions contemplated by the plan have been completed, and the plan has terminated in accordance with its terms.

The acquisition and sale of shares of the Company's common stock reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 23, 2026. All transactions contemplated by the plan have been completed, and the plan has terminated in accordance with its terms.

The options vest ratably over a four-year period beginning on February 28, 2026.

The transaction was executed in multiple trades ranging from $308.38 to $309.36. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $304.07 to $304.98. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $304.07 to $304.98. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $310.44 to $311.41. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $305.19 to $306.00. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $306.00 to $306.99. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $307.38 to $308.37. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $306.38 to $307.37. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $311.50 to $311.77. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $309.04 to $310.01. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $309.43 to $310.38. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $308.03 to $309.01. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The Reporting Person may be deemed to beneficially own shares of the Issuer's common stock directly owned by the Reporting Person's spouse, Suma M. Krishnan. Such shares and transactions by the Reporting Person's spouse are not included in this Form 4, as they are being reported separately on a Form 4 filed by his spouse. The Reporting Person disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein.

The sales reported were pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 4, 2025. The Rule 10b5-1 trading plan started on December 4, 2025, and will terminate on December 4, 2026, or earlier in accordance with the terms of the Rule 10b5-1 trading plan, including upon completion of the sale of all of the shares of the Company's common stock subject to the Rule 10b5-1 trading plan.

The transaction was executed in multiple trades ranging from $310.06 to $311.00. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $303.05 to $303.82. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $302.05 to $303.01. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $311.07 to $311.77. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $302.05 to $303.01. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $307.03 to $308.02. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $303.05 to $303.77. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The Reporting Person may be deemed to beneficially own shares of the Issuer's common stock directly owned by the Reporting Person's spouse, Krish S. Krishnan. Such shares and transactions by the Reporting Person's spouse are not included in this Form 4, as they are being reported separately on a Form 4 filed by her spouse. The Reporting Person disclaims beneficial ownership of such shares except to the extent of her pecuniary interest therein.

The sales reported were pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 4, 2025. The Rule 10b5-1 trading plan started on December 4, 2025, and will terminate on December 4, 2026, or earlier in accordance with the terms of the Rule 10b5-1 trading plan, including upon completion of the sale of all of the shares of the Company's common stock subject to the Rule 10b5-1 trading plan.

The sales reported in this Form 4 were pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 23, 2026. The Rule 10b5-1 trading plan will terminate on December 31, 2026, or earlier in accordance with the terms of the Rule 10b5-1 trading plan, including upon completion of the sale of all of the shares of the Company's common stock subject to the Rule 10b5-1 trading plan.

The Reporting Person may be deemed to beneficially own shares of the Issuer's common stock directly owned by the Reporting Person's spouse, Krish S. Krishnan. Such shares and transactions by the Reporting Person's spouse are not included in this Form 4, as they are being reported separately on a Form 4 filed by her spouse. The Reporting Person disclaims beneficial ownership of such shares except to the extent of her pecuniary interest therein.

The sales reported in this Form 4 were pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 4, 2025. The Rule 10b5-1 trading plan started on December 4, 2025 and will terminate on December 4, 2026, or earlier in accordance with the terms of the Rule 10b5-1 trading plan, including upon completion of the sale of all of the shares of the Company's common stock subject to the Rule 10b5-1 trading plan.

The transaction was executed in multiple trades ranging from $256.68 to $257.67. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $262 to $262.8. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $266 to $266.93. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $264.2 to $265.19. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $261.07 to $262.04. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $260.07 to $261.06. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $265.235 to $266.19. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $266.36 to $266.93. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $263.19 to $264.1. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $259.07 to $260.06. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $257.89 to $258.765. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $265 to $265.73. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $257.93 to $258.92. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The transaction was executed in multiple trades ranging from $261 to $261.99. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.

The Reporting Person may be deemed to beneficially own shares of the Issuer's common stock directly owned by the Reporting Person's spouse, Suma M. Krishnan. Such shares and transactions by the Reporting Person's spouse are not included in this Form 4, as they are being reported separately on a Form 4 filed by his spouse. The Reporting Person disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein.

The sales reported were pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 4, 2025. The Rule 10b5-1 trading plan started on December 4, 2025 and will terminate on December 4, 2026, or earlier in accordance with the terms of the Rule 10b5-1 trading plan, including upon completion of the sale of all of the shares of the Company's common stock subject to the Rule 10b5-1 trading plan.

The transaction was executed in multiple trades ranging from $256.81 to $257.75. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein.