**Question 906** effective rate, return types, net discrete return, return distribution, price gains and returns over time

For an asset's price to double from say $1 to $2 in one year, what must its effective annual return be? Note that an effective annual return is also called a net discrete return per annum. If the price now is ##P_0## and the price in one year is ##P_1## then the effective annul return over the next year is:

###r_\text{effective annual} = \dfrac{P_1 - P_0}{P_0} = \text{NDR}_\text{annual}###