  We show how topologically stable superheavy magnetic monopoles and primordial
black holes can be generated at observable levels by the waterfall field in
hybrid inflation models based on grand unified theories. In $SU(5) \times
U(1)_\chi$ grand unification, the monopole mass is of order $4 \times 10^{17}$
GeV, and it carries a single unit ($2 \pi /e$) of Dirac magnetic charge as well
as screened color magnetic charge. The monopole density is partially diluted to
an observable value, and accompanied with the production of primordial black
holes with mass of order $10^{17}$-$10^{19}$ g which may make up the entire
dark matter in the universe. The tensor to scalar ratio $r$ is predicted to be
of order $10^{-5}$ - $10^{-4}$ which should be testable in the next generation
of CMB experiments such as CMB-S4 and LiteBIRD. The gravitational wave spectrum
generated during the waterfall transition is also presented.
