According to Michael Greeson of TDG, the biggest growth of Live TV Streaming Services is coming from Hulu Live TV. Based on their estimates, the service has surpassed 2 million subscribers in the first quarter, after announcing they had reached 1 million subscribers in September.
Overall, he estimates that there are 8.4 million Live TV Streaming Services subscribers. Sling TV is still the largest vMVPD with 2.42 million subscribers, ahead of DIRECTV NOW who lost another 83,000 subscribers this quarter leaving them with just 1.5 million.
Hulu Live TV announced in September that they had reached 1 million subscribers, but TDG speculates that they have surpassed 2 million subscribers. Greeson speculates that the remaining services have ~2.4 million, up from 1.4 million year ago. fuboTV announced in September that they had 250,000 paid subscribers, so the bulk of those subscribers are likely using YouTube TV, with some using Philo.