Craziest day I've seen. ES went limit down and was halted in...

Craziest day I've seen. ES went limit down and was halted in premarket! After closing at yearly highs last week, VIX was up almost 100% on the open! And at one point the biggest NASDAQ ETF (QQQ) was down 16%! Interactive brokers pulled all intra day margin and banned short selling on equities, well TD ameritrade took their whole platform offline and customers couldn't even execute trades/ close out positions- options markets were so wide market makers were hesitant to step in! Also, during the big mark down on the open there was less liquidity around than during the flash crash!