Volatility
The size of an asset's price swings over a period, usually expressed as an annualised standard deviation of returns.
Crypto volatility is several times that of equities; bitcoin moving 2% in an hour is routine. Coinmico's Fear & Greed index ranks the last month's realised volatility against the past year — calm advances read as confidence, violent moves in either direction as fear. Leverage must be sized to volatility, not to what an exchange offers.