Home Implementing a for loop of share prices
 I need to work out a value S(n) based on the equation s(n) = (1 + r(1))(1+r(2))...(1+r(n))  The value of S(after N days) = (1+r(after 1 day))*(1+r(after 2 days))...(1+r(after N days))  with r coming from: r = return_daily + sig_daily  but calculated D times (see code below, D is calculated once for each day and is a random value) I'm just not too sure how to implement the equation including a changing variable(r changes daily). Thanks for any help Relevant Code: #import all modules required import numpy as np # using different notation for easier writting import scipy as sp import matplotlib.pyplot as plt #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #collect variables provided by the user period = 63 # can be edited to an input() command for variable periods. Return_annual = np.arange(0.00,0.15,0.05) # creates an array ??? not sure if helpful sig_annual = np.arange(0.01,0.31,0.01) #use .31 as python doesnt include the upper range value. #functions for variables of daily return and risk. Return_daily = (1/252)*R_annual sig_daily = (1/(np.sqrt(252)))*sig_annual D=np.random.normal(size=period) r_i=Return_daily + sig_daily # must be calculated D times