AGNC Investment has provided investors with lots of passive income over the past several years. AGNC Investment (AGNC -0.10%) is a prolific dividend stock. The mortgage-focused real estate investment trust (REIT) pays a monthly dividend that currently yields over 14%. That's more than 10 times higher than the S&P 500 (1.3% yield). The mortgage REIT has paid its monster dividend for 55 months in a row. That's impressive, considering the market conditions it has endured over the past few years. With the envir ...