On October 18, 2013, Quote/Trade ratios dropped to 3 year lows. Charts below chronicle
the average number of quotes per trade for each 5 minute period of the regular trading
session (9:30 to 16:00 ET) for all ~8000 NMS Stocks from 2007 to October 18, 2013 (through
10:45 ET). Each day is color coded by age - older dates start with purple while more
recent dates are colored red.. The horizontal red line is in the future (after 10:30
ET on October 18, 2013).
Quotes/$10K Traded (accounts for trade size drop
and changes in stock price)