Flash Crash

Flash crash is nothing but a sudden crash (fall) in the stock prices.

Such a crash might take place due to manual as well as algorithmic errors. Taking a recent example, the NSE Nifty lost 900 points (over 15%) in a matter of seconds on October 5, 2012. In this case, though the stock exchange was forced to pause trading for a while, the NSE claimed it was a human error rather than an algorithmic one which caused the crash.