  We discuss new types of instabilities of D=4 electrically charged
AdS-Reissner-Nordstr\"om black branes that involve neutral pseudo-scalars. The
instabilities spontaneously break translational invariance and are associated
with the dual three-dimensional CFTs, at finite temperature and fixed chemical
potential with respect to a global abelian symmetry, acquiring striped phases.
We show that such instabilities are present for the infinite class of
skew-whiffed $AdS_4\times SE_7$ solutions of D=11 supergravity, albeit at a
lower temperature than the known superfluid instabilities.
