From ACT Wiki
Interest rate benchmarks.
In the context of interest rate benchmarks, 'risk-free rates' include SOFR (the Secured Overnight Financing Rate) and SONIA.
The Financial Stability Board (FSB) recommended in 2014 that stakeholders should identify risk-free rates that might be used as alternatives to LIBOR.
Also known as near risk-free rates, recognising that they are not entirely risk-free.
Capital asset pricing model
RFRs should not be confused with the theoretically risk free rate of investment return, used in the Capital asset pricing model.