This is the daily notebook of Mike Santoli, CNBC's senior markets commentator, with ideas about trends, stocks and market statistics.
- The indexes drifting entirely within the week's range, until just now when the S&P 500 fell to a new low for the week. Overnight bounce attempts have been untrustworthy this month and late-day selling has been a feature — a switch that implies investors found themselves in September a bit too exposed to the popular big index stocks.
- The daily low in the S&P 500 three of four days this week was within a few points of 3330. That's where the index close Aug. 11 – a handy date from which to mark the start of the acceleration into an upside overshoot, as TSLA announced a split and the call-options chase really got going. It's also less than half a percent above the 50-day average – something often hit/breached in a correction but also an area that in bull markets typically attracts and rewards dip-buyers.