There are 2 GTAships per cohort, so 2 out of however many they accept (i would guess 5 or 6) will get tuition covered and get a modest stipend, like a traditional PhD program. Other than that, it sounds like accepted candidates are on their own. I imagine they provide guidance and help finding grants, but you're responsible for finding grant funding or professors with $$ on their grants. It sounds like the way people fund this is fluid and changes year to year. I know there are a few merit scholarships they give out too.