This is the daily notebook of Mike Santoli, CNBC's senior markets commentator, with ideas about trends, stocks and market statistics.
Testing, testing – one, two, three. The market undergoing several tests. S&P 500 testing last week's lows, Apple testing its 50-day average, tech in general testing pre-August-meltup levels and the overall tape being tested for its ability to withstand the corrections in mega-cap growth.
So far the broad market is hanging in there, but tenuously. Similar pattern from the past couple weeks: The average stock holding up OK, economically sensitive groups showing strong relative performance, even as the big-cap indexes feel the pressure of selling by investors over-committed to the growth winners.