S&P Flash Crash Part 2? NYSE Cancels Large SPY Trades During After Hours

What the hell happened here in $SPY (S&P 500 ETF)? Was this an after hours flash crash? Well, either way, the trades were cancelled. $766 million (7.2 million shares x $106.46) moved in eight seconds according to Bloomberg. That's a decent amount of money to transact for no reason. What would trigger this? I actually saw the number first on my live quote widget and had no idea what was going on. Apple and IBM reported earnings after the bell today and SPY is trading right at the 200 week moving average (DIA just broke that level). From 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.

The trades occurred on the NYSE’s Arca platform at 4:15 p.m. New York time today and priced the exchange-traded fund that tracks the Standard & Poor’s 500 Index at $106.46 compared with its opening price of $117.74.
The ETF plunged 9.6 percent over eight seconds as 7.2 million shares traded on NYSE Arca, according to data compiled by Bloomberg. The S&P 500 rose 0.7 percent to close at 1,184.71 today."

Doesn't this look similar to the flash crash in April?  Below are after hours charts showing the 106.46 print (courtesy of FreeStockCharts.com). To see the actual time/sales of each trade go to Zero Hedge.