On November 1st, there were 178 seconds where the number of quotes in BAC exceeded 17,000; a total of 3.2 million quotes. During those seconds, only 986 trades executed. For the entire session between 9:30 and 11:10, BAC had 3.7 million quotes and 51,000 trades. Which means 86% of all BAC quotes occurred in those 178 seconds. Which means it is likely that one algo from one firm (all of this quote spam is from Nasdaq) is responsible for 86% of all canceled orders in BAC.
The chart below shows the daily quote to trade ratio in BAC between 2004 and 11:10am on November 1, 2012. The spike on the right at 73 is through 11:10am on November 1st: 7 times higher than normal.
BAC - Daily Quote Counts between 2004 and November 1, 2012 (up to 12:45pm)
The spike on the right at 7.8 million is through 12:45pm on November 1st.
Table from HFT Alert:
This same form of dud munition was sent to Ford, Intel, Morgan Stanley, Yahoo, and Sirus Radio.