Volatility-based price alerts: why one percentage doesn't fit every coin

The problem with fixed thresholds

Coins don't move the same amount. Bitcoin often moves a fraction of a percent in a typical hour, while a small-cap coin can move several percent without anything special happening. Set the same percentage alert on both and you get one alert that rarely fires and another that never stops.

Volatility also changes over time. A threshold that made sense last week can be too tight after a big news day and too loose in a quiet one.

Measuring moves in σ

σ (sigma) is the standard deviation of returns: roughly, the size of a normal move. Traders Window calculates each coin's σ from its last 24 hourly returns on Binance, so it's always current and specific to that coin.

• 1σ is an ordinary hourly move for that coin.
• 2σ is unusual. In a textbook bell curve, only about 5% of moves are that large.
• 3σ is rare, or would be in a textbook. Crypto has “fat tails”: big moves happen more often than the bell curve predicts, which is exactly why they're worth an alert.

So an alert at 2σ means the same thing, “unusual for this coin, right now”, whether you set it on Bitcoin or on a meme coin.

When to use $, % or σ

• $ when you care about a specific amount, for example on a position with a fixed risk.
• % for a simple, stable rule on one coin you know well.
• σ when you watch several coins, or want alerts that adapt as the market gets quieter or wilder.

Setting it up in Traders Window

1. Open Settings → Alerts.
2. Next to a coin, type a number and switch the unit to σ. Start with 2.
3. Choose a direction with the arrow: both ways, up only or down only.

The move is measured from the price when you set the alert, or when you last dismissed it. σ is recalculated as new hourly candles close, so the threshold follows the market by itself.

For information only, not financial advice.

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