It's a rare opportunity to secure a reliable 15% dividend yield, but that appears to be the case with AGNC Investment Corp. (AGNC -3.46%) stock. On Feb. 9, the company paid a $0.12 dividend per share, the same rate it has been paying monthly for nearly four years.Is this your chance to buy into one of the market's highest-paying dividend stocks?High dividends make senseIt should come as no surprise that AGNC has paid an eye-popping dividend for years. In many ways, the entire business model is built around ...