How Fast Can Hypervelocity Stars Travel?

How Fast Can Hypervelocity Stars Travel? Even so, “hypervelocity” is normally defined as those travelling faster than 500 km per second (310 mi/s), which is fast enough for them to escape the Milky Way’s gravitational pull and eventually whiz off into intergalactic space. And S5-HVS1 is the fastest of them all. What is the fastest