See: 9/11 Trading Halt https://en.wikipedia.org/wiki/Economic_effects_of_the_September_11_attacks https://en.wikipedia.org/wiki/Economic_effects_of_the_Septem..

See: 9/11 Trading Halt https://en.wikipedia.org/wiki/Economic_effects_of_the_September_11_attacks https://en.wikipedia.org/wiki/Economic_effects_of_the_Septem... Giving people time to think and force them to slow down is a proven method to prevent all out chaos.