  We use the BlueTides simulation to predict the properties of the high-$z$
galaxy and active galactic nuclei (AGN) populations for the planned 2200deg$^2$
Wide-Field Infrared Survey Telescope's (WFIRST)-AFTA High Latitude Survey
(HLS). BlueTides is a cosmological hydrodynamic simulation, which incorporates
a variety of baryon physics in a $(400h^{-1} \mathrm{Mpc})^3$ volume evolved to
$z=8$ with 0.7 trillion particles. The galaxy luminosity functions in the
simulation show good agreement with all the current observational constraints
(up to $z=11$) and predicts an enhanced number of UV bright galaxies. At the
proposed depth of the HLS ($m < 26.75$), BlueTides predicts $10^6$ galaxies at
$z=8$ with a few up to $z\sim 15$ due to the enhanced bright end of the galaxy
luminosity function. At $z=8$, galaxies in the mock HLS have specific star
formation rates of $\sim 10 {\rm Gyr}^{-1}$ and ages of $\sim 80 {\rm Myr}$
(both evolving linearly with redshift) and a non-evolving mass-metallicity
relation. BlueTides also predicts $\sim 10^4$ AGN in WFIRST HLS from $z=8$ out
to $z\sim 14$. These AGN host black holes of $M\sim 10^6-10^8 M_\odot$
accreting close to their Eddington luminosity. Galaxies and AGN have host halo
masses of $M_{halo}\sim 10^{11-12} M_\odot$ and a linear bias $b\approx 13-20$.
Given the expected galaxy space densities, their high bias and large volume
probed we speculate that it may be feasible for WFIRST HLS detect the Baryon
Acoustic Oscillation peak in the galaxy power spectrum out to $z=8-9$.
