User:JohnStratoudakis

$$ n = number of days Day Close = x_1, x_2, ... x_n

$$

$$ Mean = \frac{\sum_{i=2}^{n} ln (x_{i-1}/x_i)}{n} $$

$$ Sum = [({\sum_{i=2}^{n} ln (x_{i-1}/x_i)}) - mean]^2 $$

$$

Volatility = 100.0 * \sqrt{252} * \sqrt{Sum/days}

$$