The symbol HYG is the iShares Corporate Bond Fund. It has a long history, and during bear markets (remember those?) its moved can be quite violent.
The HYG and SPY usually tag along together, bosom buddies, although usually corporate bonds tend to weaken in advance of equities since, let’s face it, the big bond boys tend to be smarter than the /wsb basement-dwellers. It’s a simple fact of history.
With that in mind, I’d like to point out what’s been going on recently between these two. They seem to be having a disagreement. There seems to be some divergence. And HYG isn’t quite as thrilled with life as the SPY is these days. Food for thought.