There could very well be a lot more story left to tell, which, if you’re a fan of the franchise, probably isn’t a problem at all.
As for what the future really holds for John Wick, we’ll have to check out John Wick: Chapter 3 – Parabellum to find out.
One thing that does seem clear is that this franchise isn’t being designed to be a simple trilogy, so John Wick likely won’t find an end in this entry.