Tractica estimates that more than 88% of all consumer-grade VR head-mounted displays sold in 2016 were mobile, and the firm anticipates that the mobile domination of the VR market will continue for years to come, with mobile HMDs constituting three-quarters of annual consumergrade HMD shipments in 2021. Despite the momentum behind mobile VR, however, Tractica’s analysis indicates that there is much work still to be done.