It has no feature for that. Pop ups are annoying and I don't advocate them (even if it's self triggered) so it's something you'll need to implement your self. If you're using a browser that supports tabs it'll open as a new tab otherwise it's opened as a new window.
There is the issue of links that belong to the domain though. Those should just navigate away from the stream. I've added a bug ticket to fix that behavior as links on the same domain should always just navigate to them.
forge.joomlapolis.com/issues/5479