When volume is mentioned, for the non-traders, it is important to see how it comes in and when. What you see here is the NASDAQ and it's declining volume throughout the session. This is not usually something that lasts for very long. Prior to 2009 at least.
As mentioned before anon could put up some really technically oriented charts with many indicators but these basic charts with volume and macro views suffice for the point trying to get across.
If you want moar technical charts suggest you start at stockcharts.com.