Today gave us a nice opportunity to see how the concept of participation applies to intraday time frames as well.
The May 24th entry in the Trading Psychology Weblog offers a picture of market participation on a 3 minute basis leading up to the market's swan dive late in the afternoon. This chart tracks the number of advancing minus declining NYSE stocks. We began the day with strength, but advancers waned through the day *prior* to the large drop. Just as Monday's weakness could not extend to a majority of issues, Tuesday's rising tide could not lift all boats. That's a clear negative for this market and will have me looking once more for downside participation on Wednesday.