The Fed's widely expected to cut 25 basis points today. The market is expecting almost another full cut at the next meeting, but the Fed's actions with its balance sheet are more important now. They have been shrinking the balance sheet for over two years but may need to stop due to rising money market rates, which could otherwise cause borrowing costs to rise unexpectedly and force deleveraging. Even if rates are cut, the Fed can't guarantee demand for Treasuries but can manage money market rates to keep leverage costs manageable.

The rates market will hear a Fed that is less dovish than currently priced, meaning front end rates may rise after today's decision, possibly hurting equities and risk assets because the Fed doesn't have the usual data to guide decisions.