Bitcoin Historical Volatility

The bitcoin volatility index is 30-day realized volatility: how widely BTC’s daily price changes have swung over the past 30 days, expressed as an annualized percentage. It is calculated from BTC daily closes and counts moves in both directions, so a high reading means large swings, not a rising or falling price.

How the figure is calculated

Each day, the log return is taken from one daily close to the next. The standard deviation of the last 30 of those returns is then scaled to a yearly figure:

Annualized volatility = standard deviation of daily log returns × √(periods per year)

Hypothetical example, assuming a 365-day year because bitcoin trades every day: if daily returns have a standard deviation of 2%, annualized volatility is 2% × √365 ≈ 38.2%.

How to read a reading

Dividing an annualized figure by the square root of time converts it to shorter horizons: a 36% reading implies a typical one-month move of about 36% ÷ √12 ≈ 10.4%, up or down. The conversion assumes normally distributed returns, which understates bitcoin’s record of sharp single-day moves, so treat it as a typical swing, not a ceiling.

The zone label (Low, Normal, High) places the current reading in a band. The chart pairs volatility with BTC price on a log scale, which makes it easier to compare calm and turbulent periods across very different price levels.

What moves it, and its limits

Volatility can jump on macro announcements, regulatory news or forced selling of leveraged positions; the Bitcoin liquidation heatmap shows where those positions cluster.

Because the window rolls, one large daily move lifts the reading for 30 days and then drops out at once, which can make volatility fall sharply even on a quiet day. Daily closes also miss intraday swings, so bitcoin intraday volatility can be higher than this figure suggests.

Realized volatility looks backward. Bitcoin implied volatility, derived from options prices, reflects what the options market expects next.