Might be of interest. From Andrew Willis, Globe & Mail, May 1/08

Money managers are fuming Thursday after a flurry of computer-driven trading in nickel play FNX Mining late Wednesday drove the stock price down 11 per cent and made a mess of fund performance.
FNX stock swooned in the final minute of trading on the TSX Wednesday on what traders describe as an “algorithm gone wild.” That means a computer-driven trading program went astray.
Selling done through the anonymous broker function on the TSX – traders are pointing fingers at one of the U.S. dealers – dropped FNX from $28 to $24 in the final moment of trading, with no news from the company to explain the nosedive. In the after-market, FNX shares changed hands at $23.15.
Market regulators intervened, as they do when perceived computer glitches move stocks, but the closing price on FNX ended up being set at $25.
That sharp drop, coming at the end of a month, is going to hammer performance at hedge funds and other money managers that held significant stakes in FNX. And since compensation is based on performance, the algo gone wild is going to be cursed at a number of funds.

From SH by Red Mars

Globe says "algorithm gone wild" sinks FNX Mining

2008-05-02 07:44 ET - In the News

The Globe and Mail reports in its Friday edition that James Dinan earned $470-million (U.S.) last year as head of $14-billion (U.S.) York Capital Management. The Globe's inside poopmeister Andrew Willis writes that on Wednesday Mr. Dinan's fund gave back $49-million (Canadian) of that total on a computer-driven trading error that hammered FNX Mining. York owns 19 per cent of FNX. York is FNX's largest shareholder. FNX was the victim of what traders call an "algorithm gone wild." Computer-based algorithm programs buy or sell stocks based on set criteria. Something went wrong in the final minute of trading Wednesday. An investment dealer trading through the "anonymous" function on the TSX suddenly hit the market with a series of FNX stock sales. The selling pressure dropped FNX from $28 to $24 in the final moments of trading. After-market trading saw the stock drop to $23.15. Market regulators quickly intervened. Market Regulation Services decided the closing price on FNX should be set at $25. When the market opened Thursday, FNX popped right back to $28, and it closed at $27.95. The sharp drop came at the end of the month and will hammer performance at hedge funds such as York.