  SN 2019neq was a very fast evolving superluminous supernova. At a redshift
z=0.1059, its peak absolute magnitude was -21.5+/-0.2 mag in g band. In this
work, we present data and analysis from an extensive spectrophotometric
follow-up campaign using multiple observational facilities. Thanks to a nebular
spectrum of SN 2019neq, we investigated some of the properties of the host
galaxy at the location of SN 2019neq and found that its metallicity and
specific star formation rate are in a good agreement with those usually
measured for SLSNe-I hosts. We then discuss the plausibility of the magnetar
and the circumstellar interaction scenarios to explain the observed light
curves, and interpret a nebular spectrum of SN 2019neq using published SUMO
radiative-transfer models. The results of our analysis suggest that the
spindown radiation of a millisecond magnetar with a magnetic field B~6e14 G
could boost the luminosity of SN 2019neq.
