SPY Flash Crashes: NYSE Cancels $500 Million Worth Of Trades

"Luckily for all the people who wrote in to us, and thousands more, who may have had MOC orders that got filled at 10% lower, the exchange has cancelled millions worth of trades. Per Bloomberg: "NYSE Euronext cancelled all trades in the $74.8 billion SPDR S&P 500 ETF Trust that occurred at almost 10 percent below the security’s opening price, according to an email sent by the exchange." And as presented below (which is a mere sample of all the DKed trades) there were about $500 million worth of notional that just got cancelled. The market is a farce, wrapped in a joke, inside a tragicomedy."