Nanex Research

Nanex ~ 30-Oct-2012 ~ SPY Bad Tick or Test

On October 26, 2012 at 8:30:05, two trades executed at NQ-Boston at prices far outside the NBBO. The first at 141.68 which was 0.71 above the previous trade, and the next occurring about 200 milliseconds later at 140.53, which was 0.40 lower than the previous trade (and 1.15 away from the previous trade at NQ-Boston).

A link to a google spreadsheet of these trades, or download the text file.


1. SPY ~ 1 millisecond interval showing trades color coded by exchange.
The bad prices are labelled 1 and 2.

2. SPY ~ 500 millisecond interval showing trades and quotes from NQ-Boston.


3. SPY ~ 500 millisecond interval showing trades, bids and asks from NQ-Boston and Nasdaq.


4. SPY ~ 500 millisecond interval showing trades, bids and asks color coded by exchange.



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