When someone answers "What do you think triggered the big stock market selloff Friday?"
They will come up with a large list of narratives, none of which mention positioning: People were choking on calls on Thursday, and purging all those calls on Friday.
ex: $SMH (pink) went from top right on this chart on Thursday (calls priced higher than puts in the +90% %'ile), to puts and calls being equally valued (i.e. center of chart).
Then look at how expensive QQQ options were INTO the Friday vs SPY (Y axis). Tech heavy Qs were massively overvalued related to SPY as everyone over-FOMO'd tech.
Positioning needed a reset.