Nifty feel a sharp 10-20% in no time.
As per the market understanding and information.
A big basket of Nifty 50 stocks was hit which led to some stocks like ONGC , Sesa etc falling 20 %. This led to a circuit barrier being hit at 570 points. Although the index did recover in seconds but as per the norms a freeze happens when a circuit is hit so NSE cash trades were freezed.
We can say it to be a freak trade as there was no impact on Futures Markets and Currencies.
All in all nothing to worry markets have stabilized and working normally. So no conspiracy theories just a normal butter fingers one like which happened in US also last year.