It's so hard to get an answaer here, JFGI. Part of the answer...
http://www.investopedia.com/ask/answers/07/circuitbreaker.asp
http://www.investopedia.com/ask/answers/07/circuitbreaker.asp
===========================Quote from fluttrader:
For example on 9/11 , how much time was the warning given before they closed down ?
Quote from zdreg:
banks are nationalized.
Quote from jeb9999:
The NYSE was closed for 4 business days from 09/11/01 to 09/14/01 and opened for trading on 09/17/01.
Please specify which federal regulations regulate exchange closings.
Quote from PAPA ROACH:
I may be dead wrong, but I have doubts they would shut down the market over nationalizing a bank or 2.
Quote from stts:
If you really want to know which regulation, your going to have to look it up yourself. But I am quite sure Federal law forbids 4 day closings except unavoidably 9/11. That is why they are open short days after thanksgiving and before Xmas. Thats how they cheat to half way get their 4 day holiday.
As far as the 9/11 markets open, I must have remembered wrong about when they opened. I thought they opened friday for a short period to comply with financial laws.
And yes Banks also cant be closed 4 consecative days.