Prevail nailed this one on ES vs ER2, and today's action is an easy demonstration.
ER2 @ 698, +15.5 on the day
ES @ 1267, +14.5 on the day
Looking at a short strike put 15% OTM:
ER2 ~ 590, only 30 points below the October low of 620.
ER2 JUL 590P 0.60 bid
ES ~ 1070, a full 100 points...