Chapter 4: The principles of the time value of money Flashcards
In exam - 3 questions, standard format
Time value of money - 2 key concepts
- Money received now is more valuable than the same money received in years to come. Even with interest rates being at a record low, the ability to earn interest on your capital has a value.
- A rate of interest received monthly is more valuable than the same rate of interest received quarterly or annually.
You can then earn interest on your interest received (compound interest)
What is the Present value (PV)
The amount of capital invested today
What is the Time period (n)
The time for which capital is invested is split into periods. Number of time periods is denoted as ‘n’
The time period or n refers to the number of times that interest is paid rather than the number of years it is paid for.
What is the Interest rate (r)
Interest is quoted as a percentage, in calculations it is turned into decimals. 6% is 0.06 etc…
What is the Future value (FV)
Amount available at the end of a set period.
Present value (PV) invested at a certain rate (r) for set time period (n) = Future Value (FV)
What is the basic compound interest formula?
FV = PV(1+r)n
Wherever you see a bracket next to letters, as shown with the PV (1+r)n, it is multiplication that is applied.
To do this on a standard calculator:
1+ (r as a decimal) xx (Times twice) PV, Press = (the number of times the interest is paid, so if interest is paid twice a year you would press = twice)
What would a sum of £3,000 invested at an interest rate of 4% for five years increase to?
FV = 3000(1+0.04)5
1.04 xx (times twice) 3,000(equals 5 times, once for each time period) =£3,649.96.
Don’t forget to ‘equals’ the amount for each time period. 5 years - 5 times pressing ‘=’
Jennifer, a basic rate taxpayer who has fully utilised her Personal Savings Allowance, invested £15,000 into a 3-year fixed rate bond that has a gross annual rate of 6%.
She wants to know how much this will be worth at the end of the term.
A 6% gross return will be a 4.8% net return for a basic rate taxpayer (6% - 20% = 4.8%). Decimalise this to get 1.048 xx 15,000 then press equals 3 times, once for each year invested.
1.048 xx 15,000 === £17,265.34
Using the example above, you would reduce the gross interest rate by the tax rate paid so if Jennifer had been a higher rate taxpayer you would have reduced the 6% by 40%; i.e. 3.6%, and an additional rate taxpayer by 45%; i.e. 3.3%.
Amir has invested £7,000 into a savings account that has an annual rate of 6% paid on a monthly basis. He wants to know how much this will be worth in at the end of the year.
You tell him…
6% paid monthly is 6 12 or 12 payments of 0.5%.
Decimalise this to get 1.005 xx 7,000 then press equals 12 times, once for each payment.
1.005 xx 7,000 ============ (12 equals as interest is paid monthly) £7,431.74
James has invested £15,000 in a one-year bond that has an annual rate of 5% paid on a quarterly basis. He wants to know how much this will be worth when it matures. You tell him…
5 ÷ 4 = four payments of 1.25%. You press equals 4 times as there are 4 quarterly payments.
1.0125 xx 15,000 ==== £15,764.18
A sum of £10,000 is invested for four years with interest paid at 2.5% p.a.
What is the value at the end of the term?
1.025 xx 10,000 ==== £11,038.13
Harrison invested £75,000 for one year in an account paying quarterly interest at 2.75% p.a.
What is the value at the end of the year?
2.75% paid on a quarterly basis is actually 0.6875 paid 4 times (divide 2.75 by 4 = 0.6875) so turn the 0.6875 into a decimal
1.006875 xx 75,000 ==== £77,083.87
Kate invests £5,000 in a fixed rate bond paying 4% annually for 3 years and then re-invests the entire amount for a further 2 years at 3.5% paid annually.
What is the total value at the end of the 5-year period?
Both the accounts pay annual interest so 1.04 xx 5,000 === £5,624.32 reinvested for 2 years at 1.035 xx 5,624.32 == £6,024.91
What is the effective annual rate?
The effective annual rate is the nominal rate compounded.
The basic compound formula is tweaked to help us establish the effective annual rate from our nominal rate.
EAR = (1 + r/n)n-1
On a standard calculator, you will need to provide a number to compound up from.
One method involves using £100. You will use this number to work out the percentage and simply take off the figure at the end.
Start by dividing the annual rate by the number of times it is paid as before, express as a % (1.5% would be 0.015).
1.015 xx 100 =(number of times interest is paid) then remove the 100 to get the EAR
What is the effective annual rate if the nominal rate is 6% per year, compounded on a quarterly basis?
EAR = (1 + r/n)n-1 - use £100 on a normal calculator.
Start by dividing the annual rate by the number of times it is paid as before, express as a % (e.g. 1.5% would be 0.015).
(annual rate / no. of interest payments) xx 100 =(number of times interest is paid) then remove the 100 to get the EAR
6% = 6, ÷ 4 = 1.5%. So, enter 1.015 then multiply this by 100 twice, and press equals for the number of times interest is paid, 4 in this case, as it is quarterly.
1.015 xx 100 ==== 106.14
Take off your 100 and you get 6.14%