Surging interest rates have made the last few years very challenging for the real estate sector. They've increased borrowing costs while causing a lot of volatility in asset values. AGNC Investments (AGNC 0.52%) hasn't been immune to these issues. While the mortgage real estate investment trust (REIT) invests in low-risk, mortgage-backed securities (MBS) guaranteed against credit- default risk by government agencies, it has battled volatility in interest rates and MBS spreads. That has weighed on its return ...