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.