Week 14 - Loan and Interest Rates, Bond Valuation Flashcards
What is the result of quotation of interest rates?
tradition, legislation, or unfortunately quoted in deliberately deceptive ways to mislead borrowers and investors
What is interest rate per period
most straightforward way to express an interest rate
it represents the rate per compounding period (eg monthly, quarterly, semi-annually)
NOT annualised, making it hard to compare loans or investments
What is an example of interest rate per period?
A bank offers a 2% monthly interest rate on a loan.
This does not mean the annual interest rate is 2% × 12 = 24%, because compounding effects are ignored.
What is a stated annual interest rate/ quoted rate (or nominal)?
most available rate with periodic compounding, quoted by financial institutions often used in advertising
Example of stated annual rate
A credit card states an APR of 12%, meaning 1% per month.
However, if interest compounds monthly, the actual interest paid is higher
What is effective interest rate?
most informative rate because it accounts for compounding, it shows the true cost of borrowing or true return on investment
important when comparing different loans or investments with varying compounding periods
Example of EAR
If APR is 12% with monthly compounding, the EAR is:
(1+ 0.12/12)ˆ12 - 1 = 12.68%
12.68% is the actual interest paid, not the 12% quoted
Why does EAR matter?
different industries quote interest rates differently
some countries require financial institutions to disclose APR to protect consumers
lenders may advertise a low APR while hiding high compounding effects misleading borrowers
What is the stated annual interest rate known as in the US?
annual percentage rate (APR) or nominal rate
What is APR
annual percentage rate/ stated annual rate
commonly quoted but can be misleading because it ignores compounding
What is the APR formula?
APR = the interest rate per period x the number of periods per year
Example of APR
A credit card with a 1.5% monthly rate will have an APR of:
1.5%×12=18%
However, if interest compounds monthly, the actual cost (EAR) will be higher.
How is the APR used in the US and UK?
In many countries, legal rules require APRs to be quoted
In the US and UK, certain laws require the lender to disclose the APR on all consumer loans to protect consumers
Normally, the APR is the quoted interest rate in financial news or newspapers
How does the APR vary internationally
Some countries require APR to include fees & additional costs.
Others use a simple interest rate times number of periods formula
What is the APR if the monthly rate is 0.5%?
0.5 x 12 = 6%
What is the APR if the semi-annual rate is 0.5%?
0.5 x 2 = 1%
What is the monthly rate of the APR is 12% with monthly compounding?
12%/12 = 1%
What is the frequency of compounding?
some investments pay interest more than once a year (eg semi-annual interest rate that compounds twice a year)
The more frequently interest compounds, the higher the actual return (for investments) or higher cost (for loans)
Normally financial institutions will use the quoted annual interest rate (r_s) to standardise the comparison between different products
How can the same quoted APR correspond to many different compounding frequencies per year?
10% compounded semi-annually 10%/2 = 5% every 6 months
10% compounded quarterly 10%/4 = 2.5% every 3 months
10% compounded monthly 10%/12 = 0.83% every month
10% compounded daily 10%/365 = 0.02739% every day
Is more frequent compounding better?
the true interest rate (EAR) increases as compounding frequency increases
More frequent compounding → Higher effective annual rate (EAR)
For loans: More frequent compounding means you pay more interest than you might expect.
For investments: More frequent compounding means you earn more on your money
What is the future value of a lump sum formula?
FV=PV×(1+ rₛ/m)ˆmN
FV= future value
PV = present value
rₛ = quoted annual interest rate
m = number of compounding periods per year
n = number of years
This formula helps determine how much an investment will grow over time with compounding interest
What is the present value of annuity (PVA) formula?
PVA = (Cₘ/ rₛ/m )(1 - 1/(1+ rₛ/m)^mN)
PVA = Present Value of an annuity
Cₘ = Regular annuity payment per period
rₛ/m = Periodic interest rate
mN = Total number of periods
This formula is used to calculate the present value of a series of future cash flows, such as loan payments or pension payouts
What is the future value of annuity (FVA) formula?
FV_A = Cₘ [(1+ rₛ/m)^mN - 1]/ rₛ/m
FVA = Future Value of an annuity
Cₘ = Regular annuity payment
rₛ/m = Periodic interest rate
mN = Total number of periods
This formula calculates how much a series of payments will be worth in the future when interest compounds
For a £1 investment with 10% quoted rate
annually: £1×(1+0.10) = £1.10
semi-annually (rₛ∕𝑚 = 0.10∕2 =0.05) £1×(1+0.05)^2=£1.1025
quarterly (rₛ∕𝑚 = 0.10∕4 = 0.025) £1×(1+0.025)^4=£1.1038
monthly (rₛ∕𝑚 = 0.10∕12 = 0.0083)£1×(1+0.0083)^12=£1.1042
daily (rₛ∕𝑚= 0.10∕365 = 0.0002739)£1×(1+0.0002739)^365=£1.1051
continuous compounding: £1×𝑒^(0.10×1) = £1.105171
continuous compounding: 𝐹𝑉_𝑁=𝑃𝑉×𝑒^(rₛ𝑁)