Exchange

On October 19, 1987, the Dow Jones Industrial Average (DJIA) dropped 508 points, a 22.6% loss in a single day, the second-biggest one-day drop the exchange had experienced, prompting officials at the exchange to invoke for the first time the "circuit breaker" rule to halt all trading. This was a very controversial move and led to a quick change in the rule; trading now halts for an hour, two hours, or the rest of the day when the DJIA drops 10, 20, or 30 percent, respectively. In the afternoon, the 10% and 20% drops will halt trading for a shorter period of time, but a 30% drop will always close the exchange for the day. The rationale behind the trading halt was to give investors a chance to cool off and reevaluate their positions. Black Monday was followed by Terrible Tuesday, a day in which the Exchange's systems did not perform well and some people had difficulty completing their trades.
There was a panic similar to many with a fall of 7.2% in value (554.26 points) on October 27, 1997 prompted by falls in Asian markets, from which the NYSE recovered quickly.
On January 26, 2000, an altercation during filming of the music video for Sleep Now in the Fire, which was directed by Michael Moore, caused the doors of the exchange to be closed and the band, Rage Against the Machine, to be escorted from the site by security,[11] after band members attempted to gain entry into the exchange.[12] Trading on the exchange floor, however, continued uninterrupted.[13]

Security after the September 11 attacks
The NYSE was closed from September 11 until September 17,