  We study electronic instabilities of a kagome metal with a Fermi energy close
to saddle points at the hexagonal Brillouin zone face centers. Using parquet
renormalization group, we determine the leading and subleading instabilities,
finding superconducting, charge, orbital moment, and spin density waves. We
then derive and use Landau theory to discuss how different primary density wave
orders give rise to charge density wave modulations, as seen in the
AV$_3$Sb$_5$ family, with A=K,Rb,Cs. The results provide strong constraints on
the mechanism of charge ordering and how it can be further refined from
existing and future experiments.
