X0306 4 2019-04-08 0 0001459200 Alarm.com Holdings, Inc. ALRM 0001643898 Trundle Stephen C/O ALARM.COM HOLDINGS, INC. 8281 GREENSBORO DRIVE SUITE 100 TYSONS VA 22102 1 1 0 0 President and CEO Common Stock 2019-04-08 4 M 0 15000 4.00 A 237443 D Common Stock 2019-04-08 4 S 0 15000 64.71 D 222443 D Common Stock 2111235 I By LLC Common Stock 184619 I By Trust Common STock 120118 I By Trust Stock Option (Right to Buy) 4.00 2019-04-08 4 M 0 15000 0.00 D 2023-12-30 Common Stock 15000 275000 D These exercises and the corresponding sales were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.25 - $65.125, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. These shares are owned by Backbone Partners, LLC ("Backbone"). The Reporting Person has the sole power to vote and dispose of the shares held by Backbone. The Reporting Person disclaims beneficial ownership of the shares owned by Backbone except to the extent, if any, of his pecuniary interest therein. These shares are owned by the Stephen Trundle 2015 4 year GRAT (the "4 Year GRAT"). The Reporting Person is the sole trustee and primary beneficiary of the 4 Year GRAT. These shares are owned by the Stephen Trundle 2015 Gift Trust (the "Trust"). Certain members of the Reporting Person's immediate family are beneficiaries of the Trust. The Reporting Person disclaims beneficial ownership of the shares owned by the Trust except to the extent, if any, of his pecuniary interest therein. This option is fully vested and immediately exercisable. /s/ Daniel Ramos, Attorney-in-Fact 2019-04-10