2. Measuring standalone risk using realized (historical) data

Returns earned over a given time period are called realized returns. Historical data on realized returns is often used to estimate future results. Analysts across companies use realized stock returns to estimate the risk of a stock.

Consider the case of Blue Llama Mining Inc. (BLM):

Five years of realized returns for BLM are given in the following table. Remember:

1.	While BLM was started 40 years ago, its common stock has been publicly traded for the past 25 years.
2.	The returns on its equity are calculated as arithmetic returns.
3.	The historical returns for BLM for 2012 to 2016 are:

	2012	2013	2014	2015	2016
Stock return	20.00%	13.60%	24.00%	33.60%	10.40%

Given the preceding data, the average realized return on BLMs stock is20.32% .

The preceding data series represents of BLMs historical returns. Based on this conclusion, the standard deviation of BLMs historical returns is .

If investors expect the average realized return from 2012 to 2016 on BLMs stock to continue into the future, its coefficient of variation (CV) will be .