Magic SKEW-50day SMA  I made SKEW invisible on this chart; only plotted 50-day SMA of the SKEW for clarity  When SKEW-50day SMA was above 130; huge left tail risk warnings  Before Feb 2018 #Volmageddon before Oct-Dec 2018 $SPX carnage before Feb/Mar 2020 Virus crisis  obvious? face with monocle