From Ticker Sense
The S&P 500 Uptick-Downtick Index (TIKX) measures the number of stocks in the S&P 500 that have traded on an uptick minus the number of stocks that have traded on a downtick at any given time during the trading day. When the number reaches the +/- 300 level, it generally indicates a large program trade. The table below shows the daily high and low of the TIKX. While we are at somewhat of a loss for an explanation, it is interesting to point out that in the past few weeks, we have seen an increase in the high/low spread of the TIKX. This increase was preceded by a month or two of very low daily spreads.