Bitcoin volatility index after BVOL24H: how to measure it now

For years many traders kept one number on their TradingView screen: .BVOL24H, BitMEX's bitcoin volatility index. It answered a simple question — how much is bitcoin actually moving right now? — with a single figure in percent.

In September 2026 BitMEX closed its exchange, and the .BVOL24H and .BVOL7D quotes stopped updating with it. The question did not go away. Here is what that index measured and how to get the same reading today.

What .BVOL24H measured

.BVOL24H was realized volatility: it looked back at bitcoin's price over the last 24 hours and measured how large the moves were. It forecast nothing. It was built as an index under a futures contract, so it had to be one simple number — a single exchange as the source and no context attached.

The recipe is standard:

1. take the price at equal intervals — for example, every five minutes;
2. compute the log return between neighbouring points;
3. take the standard deviation of those returns;
4. scale it to a day: multiply by the square root of the number of steps in a day (√288 for five-minute data).

The result is daily volatility in percent. Multiply it by √365 to get the annualised figure — the form in which volatility is usually quoted on the options market.

What the numbers mean

A daily value of 2% means bitcoin typically travels about 2% of its price in a day. Rough guides for bitcoin:

• up to about 2% — a quiet market;
• 2–4% — an active, nervous one;
• around 5% and above — a storm: news, liquidation cascades, a trend breaking.

These bands are for bitcoin. The same 3% is a quiet day for a small altcoin — which is exactly why a bare number is hard to read.

Why a number alone is not enough

"2.4%" says little until you know whether that is a lot for this coin. The useful question is different: how does today compare with the coin's own history? Higher than on 90% of days is a storm, whatever the absolute figure.

An index built for a futures contract could not carry that context. It is the main thing we added in AXiV.

AXiV: the same formula, with context

AXiV — AxiPivot Volatility measures realized volatility the way .BVOL24H did, is updated every five minutes, and adds:

• the coin's own history on the chart — today's value against its past two weeks, three months or a year; the number's colour follows one scale for every coin: green under 3% a day, no colour 3–6%, orange 6–10%, red from 10%;
• one yardstick for every coin in the pool, not only bitcoin — so "ETH is 1.1× as jumpy as BTC" is a fair comparison;
• honest gaps — a price older than 15 minutes never enters the series, so a stalled data feed never looks like a calm market.

The live values for bitcoin and ether are on the AXiV page.

Realized is not implied

If you see a much larger number elsewhere, check what it measures. Deribit's DVOL, for example, is implied volatility: the move the options market expects over the next 30 days, quoted annualised. It answers a different question, and before big events the two diverge. We explain the difference in Realized vs implied volatility.

How to use it

Volatility says nothing about direction. It tells you how much room to expect — and that decides where a stop can go and how large a position can be. A stop that sits inside a normal day's move gets hit by noise; how the stop distance sets the size is shown in How to calculate position size with leverage.

For analysis, not for trading. Nothing here is financial advice.