金融小知識：什麼是波動率 (Volatility)？

原文出自 ForexNews.com 的「今日問答 (Question and Answer of the Day)」專欄。今天的主題是《What Is Volatility?》，特別記錄下來供日後參考。

What Is Volatility?

什麼是波動率？

Volatility is a measure for variation of price of a financial instrument over time. Historic volatility is derived from time series of past market prices.

波動率是一種衡量金融工具的價格隨著時間經過的變動方式。歷史波動率則是來自過去市場價格時間數列。

Put simply, volatility refers to the amount of uncertainty or risk about the size of changes in a security's value. A higher volatility means that a security's value can potentially be spread out over a larger range of values. This means that the price of the security can change dramatically over a short time period in either direction. A lower volatility means that a security's value does not fluctuate dramatically, but changes in value at a steady pace over a period of time.

簡而言之，波動率是指證券價值變動大小的不確定性或風險量。波動率較高，代表證券價值的變動範圍可能會比較大。這表示證券價格可以在短時間內上下劇烈變化。而波動率較低，代表證券價值不會大幅變動，但經過一段時間之後，這個價值會以穩定的速度變化。