Volatility is the size of an ordinary day
Every stop-loss, every leverage decision and every "is this a big move?" question is really a question about volatility. Realized volatility answers it with data instead of gut feel: it measures how much an asset's daily returns actually spread around their average over a recent window. A coin with 4% daily volatility routinely moves 4% in a day and nobody should be surprised; the same 4% move in a 1% volatility asset would be a five-standard-deviation shock. Without a volatility number you cannot tell the difference between normal noise and a genuine break, and you will set stops that are either so tight that ordinary wiggles knock you out or so loose that they never protect anything.
This calculator takes your pasted closing prices, converts them to daily log returns, and computes the sample standard deviation of those returns — that is the daily volatility. Annualized volatility is simply the daily figure scaled up by the square root of 365, because crypto trades every day of the year. From the daily number it reads off the expected move over any horizon using the same square-root-of-time rule, so you can see at a glance that a week is only about 2.6 times as volatile as a day, not seven times. The last input ties it back to survival: it converts your leverage into a liquidation distance and reports how many daily standard deviations away that liquidation sits. If the answer is one or two, a completely normal day can end the trade.
How to use it
1. Paste at least 10–15 recent daily closing prices, oldest first — more data gives a steadier estimate.
2. Set the current price so the expected moves are shown in today's dollars.
3. Optionally enter your leverage to see how many standard deviations of daily move separate you from liquidation.
4. Set stops beyond the 1σ daily range and keep liquidation several σ away, then size the position on the volatility position size calculator.
Common mistakes
Using too few prices. Three or four days is not a sample; a single spike dominates the estimate. Use a couple of weeks at minimum. Confusing realized with implied volatility. This tool measures what already happened; option-derived implied volatility reflects what the market expects next, and the two can diverge sharply before events. Setting stops inside 1σ. A stop closer than the normal daily move will be hit by noise before your thesis has a chance. Ignoring that liquidation can trigger intraday. The σ count here uses close-to-close moves; an intraday wick can breach a liquidation the daily close never would, so treat the σ distance as a floor, not a guarantee.
FAQ
Should I use 365 or 252 for annualizing? For crypto use 365 because it trades every day; the 252 convention is for stock markets that close on weekends and holidays. The daily number and the expected-move table do not depend on this choice — only the headline annualized figure does.
Why log returns instead of simple percent changes? Log returns add cleanly across time and handle large moves symmetrically, which makes the square-root-of-time scaling exact rather than approximate. For small daily moves the difference from simple returns is tiny.
How does this help with leverage? Your liquidation is a fixed percentage away that depends on leverage — roughly 1 divided by leverage. Dividing that distance by daily volatility tells you how ordinary or extreme a move it takes to reach it. Pair it with the liquidation calculator for the exact price.