Zusammenfassung der Ressource
standard deviation
- calculation:
Anmerkungen:
- * obtain the arithmetic mean
* obtain the set of deviations from the mean
* square each deviation
* divide the sum of the squared deviations by the number of observations to obtain the population variance
* take the square root of the variance to obtain the standard deviation
- represents the average amount by which the values in the distribution deviate from the arithmetic mean
- normal distributions
- 68.26% - two thirds within one standard deviation
- 95.5% of all observations within two standard deviations
- 99.75% of all observations within three standard deviations of the mean
- limitation
- actual returns are not neatly/symmetrically dispersed
- most long-run distributions of equity returns are positively skewed
- The most commonly used method to quantify risk
- Measures how widely dispersed are the possible outcomes around the mean expected outcome
- measures non-systemic risk