relative strength index (RSI)

A technical indicator that focuses on the characteristics of price momentum (change and velocity of price) and the likely continuation or change of momentum from overbought or oversold levels. It is formulated from measurements of the speed and size of past price moves, plotted as a single line within an oscillating zone. Securities with high RSI values can be interpreted as having overbought positions, while stocks with low RSI values can be interpreted as having oversold positions.