From @BadAlgo here is the zoom of the Stub Quote:
On 03/22/2012 there was a similar style of behavior when the BATY was quoting AAPL 20% outside its last known price:
The following chart is of Apple (AAPL) on 03/22/2012, one day prior to a quote/trade (executed on the BATS-Y exchange) halted trading in AAPL. While the bad trade on 03/23/2012 may have been a random event, the chart below shows that BATS-Y was consistently quoting 20% away from the NBBO the day prior.
For those of you unfamiliar with the SEC stub quote band, a good refresher can be found here The Legal Limit Algo and here Stub Quote Rule Violations.
The quotes shown below are within the NBBO banding boundaries for AAPL during the first 15 minutes of trading (20%), so there is no rule being broken. However, quoting far outside the NBBO range is quite common and it is surprising to see reports of the AAPL halt being a one time error that can't happen again. With quoting like this, what's surprising is that is does not happen every single day!
In the chart below, the red lines represent ask prices from the BATS-Y exchange and the blue lines represent bid prices from the BATS-Y exchange. Note the prices jumping from the NBBO (were trading is occurring, represented by white dots) to 20% away from that level and then back. The 20% NBBO banding range is shown as a pink line for the ask side and a green line for the bid side.