Investment How Stocks Work Full Size Version Share | Related Content The Rule of 72 Do you know how long it may take for your investments to double in value? The Rule of 72 is a quick way to figure it out. A Primer on Dividends A company's profits can be reinvested or paid out to the company’s shareholders as “dividends." What Is the Dividend Yield? This calculator helps determine your pre-tax and after-tax dividend yield on a particular stock.