  This study investigates the realization of R-symmetric Higgs inflation within
the framework of no-scale-like supergravity, aiming to elucidate the formation
of primordial black holes and observable gravitational waves within a class of
GUT models. We explore the possibility of an ultra-slow-roll phase in a hybrid
inflation framework, where the GUT Higgs field primarily takes on the role of
the inflaton. The amplification of the scalar power spectrum gives rise to
scalar-induced gravitational waves and the generation of primordial black
holes. The predicted stochastic gravitational wave background falls within the
sensitivity range of existing and upcoming gravitational wave detectors, while
primordial black holes hold the potential to explain the abundance of dark
matter. Furthermore, we highlight the significance of the leading-order
nonrenormalizable term in the superpotential of achieving inflationary
observables consistent with the latest experimental data. Additionally, the
predicted range of the tensor-to-scalar ratio, a key measure of primordial
gravitational waves, lies within the observational window of future experiments
searching for B-mode polarization patterns in cosmic microwave background data.
