Parkinson Range-Based Volatility Estimator

Paste one daily "high,low" pair per line to get the Parkinson (1980) volatility estimator. It's a range-based measure that uses the full high-low swing of each bar instead of the close alone, which makes it statistically more efficient than close-to-close volatility for the same number of bars.

Educational tool only, not financial advice. Range-based estimators assume no overnight gaps and can understate volatility on gappy instruments. Check it against your own plan and risk rules before you trade it.

Built by Jason Parker, founder of Trading Ranges.