This is something to be concerned about. I don't think investors have been particularly cautious just yet.

These are great conditions for companies to guide lower in.

This has been a phenomenal year for tech stocks and a lot of people want to lock these gains in and ride this out.

This is all in keeping with the general thesis that we're in the beginning stages of the economic cycle.

Investors are edgy and nervous. That tends to mark the beginnings of rotation.