  Despite numerous detections of individual flares, the physical origin of the
rapid variability observed from blazars remains uncertain. Using Bayesian
blocks and the Eisenstein-Hut HOP algorithm, we characterize flux variations of
high significance in the $\gamma$-ray light curves of two samples of blazars.
Daily binned long-term light curves of TeV-bright blazars observed with the
First G-APD Cherenkov Telescope (FACT) are compared to those of GeV-bright
blazars observed with the Large Area Telescope on board the $Fermi$ Gamma-ray
Space Telescope ($Fermi$-LAT). We find no evidence for systematic asymmetry of
the flux variations based on the derived rise and decay time scales.
Additionally, we show that the daily-binned blazar light curves can be
described by an exponential stochastic Ornstein-Uhlenbeck (OU) process with
parameters depending on energy. Our analysis suggests that the flux variability
in both samples is a superposition of faster fluctuations. This is, for
instance, challenging to explain by shock-acceleration but expected for
magnetic reconnection.
