Now I know this stuff doesn't matter until it does and I know all those trend followers out there who "just follow price" ignore this kind of thing, but the differential of NYSE new highs minus new lows has not only failed to keep pace with price but it is now breaking down.
Figure 1 is a daily chart of the S&P Depository Receipts (symbol: SPY). The indicator in the lower panel is the simple 5 day moving average of NYSE new highs minus NYSE new lows. Typically, this indicator tracks price swings fairly well and you can see that in figure 2 (below), where I have overlaid the indicator on the price chart. Two things are noteworthy regarding this indicator. First, it peaked on November 5, 2010 and it has failed to keep up with price since that time. This is the "dreaded" negative divergence, but of course, it won't mean anything until it does. Second, the indicator (as of yesterday) is now breaking down out of its range and this should mean lower prices.
Figure 1. SPY/ daily
Most measures of market health are not keeping pace with price. At the very least, these divergences should slow the market's rise. Whether the market will be "allowed" to correct is another question.
Figure 2. SPY/ daily