As sponsors of US single-employer defined benefit plans know all too well, interest rates have experienced dramatic swings in recent years. While many plan sponsors have adapted to this environment by strategically hedging their liability interest rate risk, many are still questioning the efficacy of doing so—especially when interest rates appear to be low. Yet, failing to hedge long-duration liabilities with long-duration assets is a risky endeavor that exposes the plan sponsor to significant downside risk.