A short list of points that I take into account and others may...

A short list of points that I take into account and others may relate to...

I'm sure that there are far more knowledgeable people involved in trading than me.

It would seem logical to state that people are guided by announcements ergo a lack of announcements creates a lack of guidance.

Understandably, numbers dictate many people's decision making at any given time and every investor has a different set of numbers involved.

Statistics would back-up any claim that rounded-numbers are often markers, few more so than a half-century like today. It tipped from support to resistance in relatively calm market, on relatively low volumes, as FF has pointed out.

Shareholders with large holdings have the ability to influence markets, particularly during lulls in activity.

If one has the capacity to lower or raise markets and can trade at high-frequency levels (perhaps with the aid of an algorythm), then they are just doing what many others wished they could do.

If Stop-Loss positions are set for different stocks depending upon an estimated volatility embedded in each case, then people have a 'moat' as it were to help them trade.

Discipline and good research should ultimately rule any trade decision making.

There are more that could be added, but right now these seem to be helping me to make sense of today's early morning drop and the afternoon will be just as intriguing in my view. esp.