How can i calculate the total percentage change in a portfolio(assume 100 buy in)if i have a list which shows each percentage change of each trade?

Question

I am using the following code but I am missing something

percentagechange = [-2.704974336321264, -9.75579724548381, 161.1083287764476, -2.3049580623481725, -3.2221603096622586, -2.03531529638451, -6.491786990447023, 6.232016977803179, 25.025643012929887, 8.469894128276412, -5.697378424452704, 165.4820717201802]

totalreturns = [1]

for i in percentagechange:
    totalreturns = total_returns * ((i / 100) + 1)

I tried the above code but I can't get my head around the calculation. Please help.

Answer 1

Percentege of change is defined as [ % Increase = Increase / Original Number × 100 ]

your code has a syntax error, totalreturns inside the loop is called totalreturns but also total_returns which is not defined.

But also following the formula (if I understood correctly) you would want to have something like:

percentagechange = [-2.704974336321264, -9.75579724548381, 161.1083287764476, -2.3049580623481725, -3.2221603096622586, -2.03531529638451, -6.491786990447023, 6.232016977803179, 25.025643012929887, 8.469894128276412, -5.697378424452704, 165.4820717201802]

totalreturns = [1]

for i in percentagechange:
    totalreturns = i / ( totalreturns * 100 )

Hope it helps

Answer 2

I think this is what you are asking for:

import pandas as pd

percentagechange = [-2.704974336321264, -9.75579724548381, 161.1083287764476, -2.3049580623481725, -3.2221603096622586, -2.03531529638451, -6.491786990447023, 6.232016977803179, 25.025643012929887, 8.469894128276412, -5.697378424452704, 165.4820717201802]

totalreturns = 100 * (pd.Series((percentagechange))/100 + 1).cumprod().iloc[-1]

print(totalreturns)
#716.1782520447279

I turn the list of percentage changes into a series, divide them all by 100, add 1 and calculate the cumulative product. By using .iloc[-1] I then take the last value in the series (the total percentage change). Multiplying this by the starting value of 100, the output is 716.