  We demonstrate that the recently observed $X$, $Y$, $Z$ states cannot be
purely from kinematic effect. Especially the narrow near-threshold structures
in elastic channels call for nearby poles of the $S$-matrix which are qualified
as states. We propose a way to distinguish cusp effects from genuine states and
demonstrate that (not all of) the recently observed $X$, $Y$, $Z$ states cannot
be purely from kinematic effects. Especially, we show that the narrow
near-threshold structures in elastic channels call for nearby poles of the
$S$-matrix, since the normal kinematic cusp effect cannot produce that narrow
structures in the elastic channels in contrast to genuine $S$-matrix poles. In
addition, it is also discussed how spectra can be used to distinguish different
scenarios proposed for the structure of those poles, such as hadro-quarkonia,
tetraquarks and hadronic molecules. The basic tool employed is heavy quark spin
symmetry.
