Uhhhh, circuit breakers and limits would kick in and make such a move take several days. I doubt any locked move of that magnitude could happen UP. Down, maybe.
Indeed it may take several days, but if the info makes for a move of that order of magnitude, then the cash will trade higher whilst the future will stay locked, and so the net effect will be the same. But to answer the thread - perhaps. You see news of this variety ( we are not talking about a single stock announcement here, are we ) never reaches the whole market at once. Someone is always first. They see it, they react, the price moves. And the next person, and the next. Those with this early knowledge will move the market. On this sort of occasion, it is this fact that will save the arse of those who employ stops. Personally, whenever I have a position I regard as 'large', i always always always have a safety stop. Good question though - because if it did happen like that then out come the kids from private school - but everything else belongs to the wife !!!!!!!!!!!!!!!!!!!!!!!!
300pts straight up.. lets see.. if Saudi Arabia, Syria and Iran exchanged nukes.. leaving only the oil refineries standing.. then news comes out that Haliburton just bought China.. hmm -qwik
The funny thing is that there is a greater chance the s&p would drop 300 points than go up 300 points in one day.