Rate of Change (ROC)

IntermediateTechnical Analysis2 min read

Quick Definition

A momentum oscillator that measures the percentage change in price between the current price and the price a certain number of periods ago.

Key Takeaways

  • ROC measures the percentage change in price over a specified number of periods
  • Values above zero indicate positive (bullish) momentum; below zero indicates bearish momentum
  • Divergences between ROC and price can signal potential reversals
  • The lookback period determines the indicator's sensitivity to price changes

What Is Rate of Change (ROC)?

Rate of Change (ROC) is a momentum oscillator that calculates the percentage difference between the current closing price and the closing price n periods ago. The formula is simple: ROC = ((Current Price - Price n periods ago) / Price n periods ago) × 100. The indicator oscillates above and below zero — positive values indicate upward momentum, while negative values signal downward momentum. ROC is particularly useful for identifying overbought/oversold conditions, confirming trend strength, and spotting divergences between price and momentum. A rising ROC above zero confirms bullish momentum; a falling ROC below zero confirms bearish momentum. The choice of lookback period significantly affects the indicator's sensitivity — shorter periods (9-14) capture short-term momentum, while longer periods (25-200) identify intermediate or long-term trends.

Rate of Change (ROC) Example

  • 1A stock trading at $110 with a 10-day ROC of 10% means it was at $100 ten days ago — strong upward momentum.
  • 2When ROC crosses above zero while price breaks resistance, it confirms the bullish breakout with momentum support.