  We present new results on the rest-frame UV luminosity function (UVLF) and
stellar mass-to-light (M/L) ratio of bright (M$_{\rm UV}\lesssim-20$ mag)
spectroscopically-confirmed galaxies at $z=7-9$ derived from the BoRG-$JWST$
survey, a unique data set of NIRSpec prism follow up of $HST$-selected sources
from random-pointing imaging. By selecting galaxies from over 200 independent
sight lines, the survey minimizes cosmic variance ensuring a statistically
robust sample of the bright-galaxy population during the epoch of reionization.
The data is used to constrain, for the first time, the bright end of the UVLF
at $z=7-9$ from spectroscopically-confirmed galaxies over eight independent
fields. We find that the bright end of the UVLF is higher than found using
imaging over $JWST$ legacy fields, suggesting the latter may be significantly
affected by cosmic variance, and thus reducing the tension with recent findings
from $JWST$ at $z>10$ and comparable to models invoking little dust attenuation
and bursty star formation. Additionally, we use the galaxies' $JWST$ spectra to
infer their stellar masses and M/L ratios relative to other $HST$ and $JWST$
studies. We show that the stellar mass scales almost linearly with UV
luminosity (M$_* \propto L_{\rm UV}^{0.85\pm0.12}$), albeit with large
($\sim0.5$ dex) intrinsic scatter, consistent with stochastic bursts of star
formation in early galaxy formation.
