Volatility
In short Volatility is how much and how fast a token's price swings. Higher volatility means bigger moves up and down, so gains and losses come quickly.
Volatility describes how much an asset's price moves over a period of time, and how quickly it moves. A token that drifts 1% in a day has low volatility, while one that swings 30% in an hour has high volatility. It says nothing about direction, only about the size of the swings, so a token that spikes wildly and one that crashes violently are both volatile.
Traders usually measure it as the standard deviation of returns over a window, such as 30 days, and often annualize the number. You will also see it described loosely as the gap between daily highs and lows. Bitcoin has historically moved far more than stocks or gold, and small tokens tend to move far more than Bitcoin. Thin liquidity is the main reason: when a pool or order book holds little money, a modest buy or sell shifts the price a lot.
For anyone holding tokens, volatility cuts both ways. It is what makes a 10x possible, and it is also what makes a 90% drawdown possible within days. It also has practical side effects: slippage rises on volatile tokens, stop-loss orders can fill far below the trigger price, and leveraged positions get liquidated on moves that would be harmless without leverage.
Before buying a small token, look at how deep the liquidity is compared with the size of your trade, and compare daily trading volume with market cap. Check how concentrated the holdings are, because one large wallet selling can cause a violent swing on its own. Size your position so that a drop of 50% or more would not force you to sell at a bad time.
Be careful about reading a quiet chart as safety. A brand-new token with few trades can look calm until one large order hits it. Also keep in mind that volatility is not the same as fraud risk, although the two often show up together on tokens with little liquidity and a few big holders.