What's Up With Bonds Decoupling From Oil, Etc.?

On the average trading day in the past few months, if oil prices were down, and especially if other bond markets were rallying, U.S. bonds were probably rallying too.  Today was the opposite and there are no glaringly obvious reasons. It's the sort of trading session where analysts must go hunting for narratives to fit the unexpected trading action. The quarry of such hunts is fairly limited. There's the notion of an "ongoing reaction to last week's Fed announcement" (which we don't love considering there was already a friendly bounce on Thursday) and from there things get even less concrete, though not necessarily wrong. The upcoming Treasury auction cycle could indeed be causing some hesitation to buy at the start of the week. There's also some buzz surrounding military re-provisioning, which continues to imply ever-higher government debt issuance (a double whammy on auction week).  Either way, the recent range remained easily intact, so while it's a bummer for today, it's not exactly an emergency.