I have designed a "Price Acceleration" Indicator (PAI). It tracks the second derivative in price movements. This is different from ROC as that one measures Price Velocity rather than Acceleration. This Indicator should give you an idea of when the steam has come out of a move, or when one is getting started. For example, if RSI is reaching overbought, and PAI is Negative, that means the move is slowing down and likely to give in to the opposite direction soon.