Many Different Investors
The example talked about Meghan and Drew, however billions of shares of stock are not owned by individual people at all!
One example is a Mutual Fund Company. They buy and sell shares of stocks of many different from the money given to them by their own investors. They buy a complete portfolio of stocks (for examples, they may invest their money in Coca Cola, Microsoft, McDonald's and Walmart at the same time). Investors don't buy the shares of the companies, they units of the overall portfolio. When the total value of stocks in the portfolio rises, the unit value increases.
In return for managing their investors money, mutual fund companies typically charge various types of fees. These may include front-end load orcommissions. This means that some money received from the investor is given to the company and not invested. Some funds are back-end loads, which means the commission isn't charged until the investor sells (redeems) his units. Some funds are no-load funds, meaning there is no commission. Additional fees may include 12b-1 fees or Management fees.
These funds management portfolios for many different people. You may have heard of a 401K, IRA, or 403b plans. These are retirement plans, where employees set aside a portion of each paycheck which is invested in a mutual fund until they retire. They invest hoping that the stock market will rise, so their small investment each paycheck grows into a bigger investment so they can have a comfortable retirement.