Volatility
Etymology
From Latin volatilis, "flying, fleeting" (from volare, "to fly"). It first described substances that evaporate readily — quick to take flight. Finance borrowed the sense of something restless and fast-moving to describe prices that will not sit still.
noun · /vol-uh-TIL-ih-tee/
The degree to which a price swings up and down over time; high volatility means large, rapid, unpredictable moves.
What it names
It measures not whether an investment goes up but how wild the ride is — the difference between a steady savings account and a stock that lurches ten percent a day.
Example
He shifted savings he would need soon out of the market to avoid its short-term volatility.
Related idea
Volatility is not the same as risk of total loss; a derivative can be volatile yet used precisely to manage risk.