think of these 4 rates as defining a corridor with an upper and a lower bound - currently 4.25% and 4.50%
the average market interest rate will sit somewhere in between
in the Federal Open Market Committee Meetings (FOMC), the Federal Reserve sets a target range - currently 4.25%โ4.50%, and then it uses the ON RRP, IORB, discount rate and SRF to steer the average rate in the market