Oversold refers to a market condition where an underlying asset has traded lower in price. The oversold condition can last for a long period of time. 

Traders use several technical indicators to determine if the underlying asset is oversold. Since traders use varying technical tools, the oversold condition of an observed asset becomes relative or subjective. Some of the technical indicators that detect oversold condition include the relative strength index (RSI) and the stochastic oscillator. 

An asset can be fundamentally or technically oversold, depending on the analytic approach of the analyst.