Volatility does not say where the price will go. It says only how hard it can jerk, and the direction is beside the point.
Why it makes the rate hold for a limited time
Once an exchange quotes a rate, it takes on the market's movement until the operation closes. The longer the window, the bigger the risk, and the wider the spread would have to be to cover it. A short lock keeps the rate closer to the market.
What to do about it during an exchange
For stablecoins, nothing: their rate against the dollar barely moves. For bitcoin and ether the moment matters, so it is wiser not to linger between creating the order and paying: that gap is exactly where the price runs.
When the swings are strongest
On news and at weekends. The crypto market runs without a break, but there are fewer participants on a Saturday, and an order of the same size moves the price more visibly. Sharp moves happen more often at night Kyiv time, along with the opening of the American session.
What it means for your exchange
If the rate is locked, nothing: the exchange has taken the risk. If the lock has expired, the order is recalculated at the new rate, and that can turn out either better or worse.
So the lock duration is not a formality in the terms but the main thing worth reading before exchanging a large amount.
Read more: Why price forecasts cannot be trusted