SOFR is published by the New York Federal Reserve every business day for the previous business day:
2.10% on August 21, 2019
The Secured Overnight Financing Rate (SOFR) is intended to replace the US dollar London Interbank Rate (US LIBOR) in future financial contracts. SOFR was selected by the Alternative Reference Rates Committee (ARRC) chaired by the New York Federal Reserve in 2017.
SOFR is the average rate at which institutions can borrow US dollars overnight while posting US Treasury bonds as collateral. Similar to a mortgage rate, SOFR is a secured borrowing rate in the sense that collateral is provided in order to borrow cash. SOFR differs from US LIBOR in that the latter is a rate for unsecured borrowing (where no collateral is posted).
Major central banks globally have taken on similar reforms to replace their US LIBOR equivalents with more reliable rates.