Volatility
Also: standard deviation
How much returns vary around their average — a common measure of risk.
Volatility is usually expressed as the annualised standard deviation of returns. Higher volatility means a wider range of likely outcomes. It is an input to the engine's scenarios, never a number the AI estimates on its own.
Volatility is useful but incomplete: it treats upside and downside swings alike and says nothing about rare, severe events. Treat it as one lens among several, alongside drawdown and stress testing, rather than the single measure of how risky a portfolio really is.