[ by Howard Haykin ] Citigroup personnel committed a fat-finger trading error which caused the share price of a stock to plunge by 99%.  The error was made in the Australia stock market and Citigroup was fined $30K by the Australian Securities and Investments Commission (ASIC), charged with breach of market integrity rules after placing a priority crossing order in shares of Fantastic Corporation in mid-May. The Citigroup trader placed a sell order for 119,231 shares of the stock at a price of $0.024, instead of $2.40.  Within seconds of the order being punched through the market price of FAN crashed to $0.024, a decline of 99%.  Citigroup cancelled the trades and contacted the ASX within 80 seconds of the erroneous execution. The regulators investigation found that the trader using a new computer not set up with the appropriate pre-set limits and warnings that would have triggered an alert when the order was made, having recently moved to a new seat in the dealing room. The $30K fine reflects the fact that this was a careless error, rather than a deliberate or reckless one, and that Citi acted quickly to resolve the error, leading to a timely resumption of trading in the stock. For further details, go to:   [Finextra, 8/28/12].