Instagram is adding a small but important new feature: The ability to mute posts from an account you follow, without actually unfollowing it.
Instagram is preparing to launch a couple of new useful features, including a mute option and a “You’re All Caught Up” indicator. The mute feature allows you to hide photos from specific users in your feed without having to unfollow them. And the “You’re All Caught Up” indicator shows you whether you have seen all of the photos and videos posted within the last 48 hours by users you follow. Source