Reader Bruce asks:

I keep hearing the market is oversold.   Or someone will say (including yourself) that a stock is oversold.
What exactly does oversold mean and how does one determine something is oversold?

Bruce, there are many definitions for oversold, some involving complicated indicators like stochastics.  I prefer the simpler "know it, when you see it" approach.  That is, if the drops looks unsustainable -- say, down big 2 days in a row -- it's "oversold." 

For example, the S&P is now down 5% in the past 5 days.  So at that rate, the market will be down 100% in about a month!  Now, it's unlikely we'll get to "down 100%" so that makes the current move unsustainable, and hence, oversold.