SOFR, IORB, EFFR

 US monetary policy studies : 

• 1. Borrowers of cash, sell repurchase agreements (repos). Lenders of cash, buy repos. Repo sellers put down USTs as collateral. This market determines the Secured Overnight Financing Rate (SOFR).
• 2. The Fed lends to banks, charging Interest on Reserve Balances (IORB). Banks lend to banks, determining the Effective Fed Funds Rate (EFFR). 
• 3. Positive IORB-EFFR @ IOER spread, and positive IOER-SOFR spread, signify ample market liquidity.