Settings > General > Posts > Mark as Read on Scroll
And if you want to never see them:
Settings > Account preferences > Show read posts
Delete or hide?
Good point. Hide is fine. I’m thinking of something like the Feedly setting where if you scroll passed a post you never see it again
I don’t think so. You can “auto-read on scroll” in Settings, but you’d have to manually “clear all read” items in the kebab menu when you’re viewing your feed.
Edit: I think you can get the effect you’re looking for by going into Settings and turning on the auto-read and going into Settings > Account Settings and turning off “Show read posts”
There’s an option to hide read posts in your profile.