Stock speculation is a big business. Trillions of dollars are exchanged on a daily basis in the stock market. If you're savvy, you can make some serious cash buying and selling stock, either short or long. What is stock? Well, it's ownership in a company. If you own 1 share of stock in a company that has 100 shares, then you own 1% of that company. That's easy to understand, right? Real estate is really the same idea, except that your company is The Planet Earth. So, how much stock is available in Earth, Inc? Let's start with a unit of stock that would represent a detached home on the planet. For this, let's say is a quarter of an acre. There are 148,939,100 square kilometers of surface land on Earth [1]. Now we need to find out how many acres are on the Earth so that we can determine the number of shares in the company. 1 acre = 4046.85 sq meters [2] 1 sq-km = 1,000,000 sq meters 1 acre = 0.00404685 sq km For simplicity, let's create 1 share of surface a