With the Federal Reserve’s recent announcement that is will drop interest rates, many investors are asking how a rate change could impact their portfolios. One of the most important — yet often misunderstood — relationships in finance is that between interest rates and bond prices. In this article, we’ll break down how they interact and why changes in rates can directly affect the value of your bond holdings.

From conversations I’ve had, most investors have a firm grasp of why stocks move up and down (because of market trends, economy, or...