I am pretty dumb dude so take this with a grain of salt .
Majority AI today can create/simulate a "Moment" but not the whole "Process". For example,You can create a "short hollywood movie clip" but not the whole "Hollywood movie". I am pretty sure my reasoning is incorrect so I am commenting here to get valid feedback.
In my humble opinion,It would be 0 as there is no transaction taking place. The original question is about stock buyers not stock holders which is often related but not always.
I wonder if there could be an option to share the generated ai subtitiles so there is no duplicate effort. For example Movie_torrent.vlc subs can be shared on some other users machine with the same Movie_torrent.vlc file.
Obv you can find majority of subs online for popular files but niche cases usually have low subs available and sharing AI could help the ecosystem.