Well, every cosmic ray makes you hypervelocity too I guess. But to be meaningful you want to talk about speed relative to your local galactic frame or some suc

Well, every cosmic ray makes you hypervelocity too I guess. But to be meaningful you want to talk about speed relative to your local galactic frame or some such. Most of the mass around us is moving relatively slowly to one another. That makes these fast stars an anomoly. And it means their (relative) effect is going to be interesting.