DoubleLine's Jeff Gundlach often refers to the copper/gold ratio as a proxy for U.S. yields. Although this is comprised of two commodities that tend to do well in rising inflation, it can be seen as a growth proxy as well, which in turn filters into where yields are moving.
Market participants often allocate to copper when growth is trending higher and, conversely, gold when growth is muted. We currently have a record net-short positioning on copper which could suggest yields may move higher.