For example on 9/11 , how much time was the warning given before they closed down ?
Quote from stts:
Probably everybody ran and they halt trading immediately. The exchanges dont warn people so they can dump their portfolio before pulling the plug. But they had to open the next day for at least a shortened session per federal regulations because they can only be closed 3 days in a row.
Quote from pt199:
What did the futs do at the time of first impact?...I bet the ES CME didnt close til the 2nd impact!