X0306 4 2021-12-31 0 0001819493 Xos, Inc. XOS 0001559238 Mattson George N C/O XOS, INC. 3550 TYBURN STREET, UNIT 100 LOS ANGELES CA 90065 1 0 0 0 Common Stock 2021-12-31 4 A 0 2580 0.00 A 116010 D Common Stock 3973525 I By LLC The shares reported in this transaction represent Restricted Stock Units ("RSUs"). The RSUs reported vested immediately on the date of grant. The RSUs were issued to the director in lieu of their cash retainer. Shares are held by NGAC GNM Feeder LLC ("NGAC"). The Reporting Person may be deemed to beneficially own such shares by virtue of his shared control over NGAC. The Reporting Person disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein. /s/ Kim Merritt, Attorney-in-Fact for George N. Mattson 2022-01-04