Here are some representative interest rates as reported in March. The relationships among them change daily, so check current yields before committing money.
General purpose money market funds 13.64%
Money market funds investing exclusively in securities 12.88%
guaranteed by the U.S. government n1
Money market funds investing in short-term tax-exempt 7.19%
securities n1 (equivalent to a taxable yield of 13.34% for
a corporation in the 46% tax bracket)
U.S. Treasury Bills maturing in 13 weeks ($10,000 minimum) n2 12.45%
Commercial paper placed by General Motors Acceptance 13.625%
Corp., maturing in 30-59 days n2
Certificates of deposit issued for 30 days by major banks 13.65%
($100,000 minimum) n2
Overnight repurchase agreements n3 12.5%
Prime rate n2 16%-16.5%
n1 Average yields for the week ended March 10, as reported by Donoghue's Money Fund Report.
n2 Rates as of March 4, as reported by the Wall Street Journal.
n3 Rate on $100,000 negotiated directly with the First National Bank of Boston as of March 9, as reported by the bank.