Create reality stock market by firm

1 down vote favorite Let's say that I live in my own world, with 20 inhabitants. I own a firm called mc Donald's. ( my people purchase food there of course). Each income to mc Donald's gets into the firm bank. McDonald's is also tracking profit each hour , day, week and month. As McDonald's owner , I will be able to take out any of the profit whenever I want to. Here comes the question Let's say I want to make mc Donald's a stock market , where my inhabitants can buy and sell stocks on mc Donald's firm. How can I accomplish this ? How and what algorithms can I use to do stock price changes to make it appear to be working like how real stock firms works ? How many stocks should I allow the firm to have ? Any suggestions or spoon feed on how I can make this mc Donald's function like a stock market in itself ? What will be needed for a price drop / increase on the stock's price ? This is what i need done. in short. be able to make some mongodb table`s firm to a reality stock market. Attached image expaining what to do , including brownian motion.