def standard_and_poors(work_days):
    counter = 1
    percentage_gain = 1
    return_on_investment = 0
    investment_per_day = 100
    while counter <= work_days: 
        print (f"n ROI on day{counter} after investing {investment_per_day} is ${return_on_investment}")  
        return_on_investment += percentage_gain 
        percentage_gain *= 1.02739726027 
        #program accounts for fluctations in stock price per day
        percentage_gain = 1.02739726027 * 0.5
        counter += 1 
    return f"n ROI after investing {investment_per_day} after {counter} days is ${return_on_investment}"
days = int(input("How many days of ur life did you invest for? "))  

The S&P 500 index fund returns an 11% average per year, which is + 0.02739726027 % per day. The average days worked over a lifetime is 90,000 hours, or 3715 days. My program aims to calculate the ROI after investing $100 for every day you work until you retire.

I am having difficulty accurately accounting for fluctuations in the stock price per day, as profit is of course not consistent on a day to day basis. I am not that good at math, so I’m unsure if there is a cool algorithm to randomly generate profit and loss increments into the ROI calculation .

I tried accounting for fluctuations by reducing the ROI by a half every other day , but that seems too linear. Thinking about it, I believe some sort of rand function would work, though I don’t know what would be the proper syntax for setting up the range.