X0306 4 2021-07-26 false 0001724570 DATTO HOLDING CORP. MSP 0001828638 FASS MICHAEL GLENN 101 MERRITT 7 NORWALK CT 06851 false true false false See Remarks Common Stock 2021-07-26 4 M false 17500.00 10.00 A 17500.00 D Common Stock 2021-07-26 4 S false 17500.00 26.25 D 0.00 D Options (Right to Buy) 10.00 2021-07-26 4 M false 17500.00 0.00 D 2028-06-20 Common Stock 17500.00 297500.00 D The exercise and sale reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on December 16, 2020. This transaction was executed in multiple trades at prices ranging from $26.01 to $26.45 per share. The price reported reflects the weighted average sale price. Upon request by the Issuer, any security holder of the Issuer or the staff of the SEC, the Reporting Person undertakes to provide full information regarding the number of shares sold at each separate price within the range set forth in this footnote. These options vested 25% on December 7, 2018 and then quarterly thereafter at a rate of 6.25% as long as the Reporting Person continues to be employed as of each respective vesting date. General Counsel & Chief People Officer /s/ Adam Collicelli, by Power of Attorney 2021-07-28