An inversion between the 2yr UST yield and the Federal Funds effective rate normally does not exceed -1%. When that happens, it's an indication the bond market is not getting the reaction from the Fed that it "expects" (or maybe it is a "want"). Inversions of this degree have normally been unkind to the equity market, but that is clearly not the case here in late 2023. Something to keep an eye on as the calendar turns to 2024.