Volatility
The degree of price fluctuation of an asset. Bitcoin's is high (the rate jumps), stablecoins' is near zero (pegged to the dollar).
In more detail
High volatility (as with Bitcoin) means the rate can change noticeably within minutes — both a risk and an opportunity. Stablecoins have near-zero volatility, so they are handy for locking in value. When exchanging a volatile asset, do not delay between checking the rate and placing the order: the price may move.
