X0306 4 2021-10-11 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 2021-10-11 4 M 0 25000 4.00 A 290616 D Common Stock 2021-10-11 4 S 0 25000 77.66 D 265616 D Common Stock 259687 I By Gift Trust Common Stock 1641373 I By LLC Common Stock 9862 I By Footings Advancement Trust Stock Option (Right to Buy) 4.00 2021-10-11 4 M 0 25000 0.00 D 2023-12-30 Common Stock 25000 40000 D This exercise and the corresponding sales were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 9, 2021. 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. 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 Footings Advancement Trust (the "Advancement Trust"). The Reporting Person has the sole power to vote and dispose of the shares held by the Advancement Trust and certain members of the Reporting Person's immediate family are beneficiaries. The Reporting Person disclaims beneficial ownership of the shares owned by the Advancement 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 2021-10-13