Treasury yields tend to grab headlines, but that might not be where bond investors should be placing their attention. The real indicator worth tracking? That's a different story altogether.

While yield numbers get the spotlight, savvy fixed-income players know there's something else brewing beneath the surface that could have a much bigger impact on portfolios. It's easy to get caught up in rate movements, but missing the bigger picture can cost you.

So what should you actually be watching instead? Consider looking at the underlying forces shaping the bond market—factors that don't always make the news cycle but absolutely move the needle on returns.