  The signal induced by a temperate, terrestrial planet orbiting a Sun-like
star is an order of magnitude smaller than the host stars' intrinsic
variability. Understanding stellar activity is, therefore, a fundamental
obstacle in confirming the smallest exoplanets. We present the Lowell
Observatory Solar Telescope (LOST), a solar feed for the EXtreme PREcision
Spectrometer (EXPRES) at the 4.3-m Lowell Discovery Telescope (LDT). EXPRES is
one of the newest high-resolution spectrographs that accurately measure extreme
radial velocity. With LOST/EXPRES, we observe disk-integrated sunlight
autonomously throughout the day. In clear conditions, we achieve a ~137,500
optical spectrum of the Sun with a signal-to-noise of 500 in ~150s. Data is
reduced using the standard EXPRES pipeline with minimal modification to ensure
the data are comparable to the observations of other stars with the LDT. During
the first three years of operation, we find a daily RMS of 71 cm/s.
Additionally, having two EPRV spectrometers located in Arizona gives us an
unprecedented opportunity to benchmark the performance of these planet-finders.
We find a RMS of just 55 cm/s when comparing data taken simultaneously with
EXPRES and NEID.
