In plain English
What Volatility means
Volatility can be observed from past price changes or estimated from option prices and other market data. A volatile currency pair may move many pips in minutes, while a less volatile pair may move within a narrower range. The measure depends on the time period and method used, so two volatility figures are comparable only when their calculation basis is clear.
Why it matters
Volatility affects execution because quotes can change before an order reaches the market. It can contribute to wider spreads, reduced displayed depth, slippage, stop-order fills away from the trigger price, and margin pressure on leveraged positions. These effects are possible rather than guaranteed, and conditions can change rapidly.
Example
Assume EUR/USD trades between 1.1000 and 1.1010 during one quiet hour, a 10-pip range. During a data release it trades between 1.0960 and 1.1040, an 80-pip range. The second period is more volatile by this simple range comparison, though formal measures may instead use returns and statistical methods.
Quick answers
Common questions
Does high volatility always mean low liquidity?+
No. They are related but distinct. Volatility can reduce displayed depth and widen spreads, yet substantial trading may still occur. Execution quality, price impact, volume, and quote refresh all provide relevant context.
How does volatility affect a stop order?+
After a stop order triggers, rapid price movement can mean the resulting order executes away from the trigger level. The size of any difference depends on available liquidity and the order’s handling rules.
Sources