It's just limit up, it is not a circuit breaker. Pre-market has limit up and limit down. Real time trading hours has circuit breakers. EDIT: Seems I might be wrong here in this case, not sure. I know limit down pre-market is 5% and doesn't move until bid out strips ask. But I see QQQ/SPY trading and NQ/ES not, just woke up so maybe not thinking this through. Someone feel free to correct me.
it is till market opening I do not know why but.... maybe because those who have shares and not futures can have the same opportunity
all futures trades are 'settled' at end of day. the market makers of the futures ran out of cash to trade. they had to wire the money to their clearing house. and fed had to print new cash to wire it.. 10% crash is more than lock limit 10% for the index is not normal...at all. market orders don't get filled. you might as well shut down the exchanges for two weeks. the market is broken.
Well that may be true, but it's also nothing more than an equal and opposite reaction to the markets going virtually straight up along with all other actions taken by fed and etc in the past years / decades. Not many people complain or act surprised than, only when the opposite happens (of course I understand why this is, but just speaking purely from an emotionless stand point)