Chapter II: Understanding Price Volatility behaviour is essential to assessing the risk associated with positions across different time spans. |
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Volatility is defined as the price range for a period, divided by the average price for the period: So, to derive the Daily Volatility on 2/15/2011 of 1.9%, the price range for the day (0.86) was divided by the average price (44.16). The Daily Volatility is obtained by dividing the daily range by the daily average. A longer Volatility period such as Weekly Volatility is obtained by dividing the weekly price range by the weekly mean price. It is important to avoid confusing this with the weekly average of the daily volatility, which is a completely different concept. The red plot shows the actual price. Volatility, as measured through various intervals, ( Daily, Weekly, Monthly and Quarterly) is plotted according to color. Investors often make a distinction between the concept of Volatility, and the concept of Risk. Academics define them to be exactly equivalent, but as can be seen here, there is good reason to distinguish between the levels of volatility or risk experienced across different time frames. During 23 years, the Average Quarterly Volatility of VMC stock price has been 20% while the Average Daily Volatility has been 2%. |
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If you have ever seen a "yield curve" you should be able to understand the concept behind this "yield curve". These Volatility Curves each apply to a discrete time interval. As the timespan across which Volatility is measured increases, the Volatility is expected to increase. The relationship between the length of time, and the expected change in price, is not linear, as is demonstrated by this chart. |
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A frequency distribution of the green points on the first chart (the daily volatility) yields this histogram. |
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Similarly, the purple points on the top chart, the Quarterly Volatility Values, are subjected to frequency distribution here. |
Refined Volatility Risk Analysis for VMC : |
| In the news, Friday, February 18, 2011: An unfavorable condition has developed with Aetna Inc., ticker symbol AET. Also, there are breaking events concerning Dollar Tree, Inc. (DLTR) and First Niagara Financial Group Inc. (FNFG) |