Yields on callable bonds tend to be higher than yields on noncallable, «bullet maturity» bonds because the investor must be rewarded for taking the risk the issuer will call the bond if interest rates decline, forcing the investor to reinvest
the proceeds at lower yields.
Depending on where the stock market and bond market are
at the time, I'd like to deploy $ 300,000 of the
proceeds in
low risk investments that have a high chance of producing a 4 % gross
yield.