The word is that yesterday’s substantial sell-off in the higher volatility, high momentum stocks were hedge funds re-balancing their portfolios volatility. Because VIX has moved from 11-12 all the way up to as high as 16 yesterday, the avg. fund has taken on too much intended risk/volatility and the adjustment brings then in-line with where they need to be. Whether or not this is true, what is true is that the big names like NFLX, TSLA, GOOG, and AMZN, along with many and many bio-techs have gotten way ahead of themselves (easy money as they say) and easy money eventually disappears, as it did yesterday.
The market is slightly oversold today and due for a bounce.