Among widely followed indicators, we can see some of this in the declining number of individual stocks
achieving new 52 - week highs when the
major market indices push higher, by the tendency for trading
volume to become dull on advances and expand on declines (or what is a similar observation, the tendency for the market to make little progress on heavy up -
volume and substantial downside progress on light down -
volume), and in the recent explosion of insider selling.