If you make a monthly investment of the X, and you know your monthly rate of return R, what’s the formula to calculate the future value in n months?
I didn’t quite ask this clearly. Let me re-explain.
I am adding the complexity that every month a recurring amount is being added.
Interest rate is negative, losing money, 1% per month
Month 0, deposit $100 = MO
Month 1, 100 + 0.99 x MO = M1
Month 2, 100 + 0.99 x M1 = M2
Month 3, 100 + 0.99 x M2 = M3