Volatility
The scale of price swings over time: usually the standard deviation of daily returns (e.g. over 30 days).
Volatility is a statistical measure of the dispersion of price changes, expressed as a percentage. It's most often computed as the standard deviation of daily returns over a window (e.g. 30 days): high volatility = violent, unpredictable moves (more risk but also more potential), low = a calm, predictable market. Crypto is a high-volatility asset class. Volatility usually rises in panic and euphoria and falls in consolidation, which is why periods of very low volatility often precede big breakouts. Don't confuse it with ATR, which measures volatility in price points from candle ranges, here it's the percentage deviation of returns.
In plain words
Tells you how much the price jumps around. High volatility = a wild rollercoaster (big risk and opportunity), low = a smooth ride. In crypto, volatility is naturally high.
Example
30-day volatility around 2% is a calm market; 8% is a violent, nervous period. Very low volatility lasting for weeks often precedes a strong breakout in either direction.
Also known as: zmienność, zmienność 30d, volatility, odchylenie standardowe zwrotów