With DJ gear you stop by pressing CUE or Pause.
With pressing CUE the track you play stops and goes back to it's begin point, where the CUE is set, or where you made a custom CUE point. Changing or adding a CUE point differents per controller.
With pressing Pause the track simply stops where it is. When pressing the same button, which changed in to Play, than the track continues, and the button will change to Pause.