Time Value of Money in Finance

Quantitative Methods

Cash Flow Additivity

Learning Outcome Statement:

Explain the cash flow additivity principle, its importance for the no-arbitrage condition, and its use in calculating implied forward interest rates, forward exchange rates, and option values.

Summary:

The cash flow additivity principle states that the present value of any future cash flow stream indexed at the same point equals the sum of the present values of the cash flows. This principle is crucial in ensuring that market prices reflect the condition of no arbitrage, meaning there's no possibility to earn a riskless profit in the absence of transaction costs. It is applied in various financial calculations including implied forward interest rates, forward exchange rates, and option pricing.

Key Concepts:

Cash Flow Additivity

The principle that the present value of a series of future cash flows, when indexed at the same point, equals the sum of the present values of individual cash flows. This ensures consistency in valuation and prevents arbitrage opportunities.

Implied Forward Rates

Forward rates calculated under the assumption of no arbitrage using cash flow additivity. These rates ensure that two investment strategies with the same cash flows have the same present value, thus preventing arbitrage.

Forward Exchange Rates

Exchange rates set today for currency exchanges that will occur at a future date, calculated to prevent arbitrage opportunities by ensuring that investment in different currencies but with similar risk profiles will yield the same return.

Option Pricing

The process of determining the fair value of options using models like the binomial model, where the cash flow additivity principle helps ensure that the option price reflects the possibility of different future states without allowing for arbitrage.

Formulas:

Implied Forward Rate

F1,1=(1+r2)2(1+r1)1F_{1,1} = \frac{(1 + r_2)^2}{(1 + r_1)} - 1

This formula calculates the implied one-year forward rate starting in one year, ensuring no arbitrage between investing for two years and investing for one year then reinvesting for another year.

Variables:
F1,1F_{1,1}:
One-year forward rate starting in one year
r1r_1:
One-year spot rate
r2r_2:
Two-year spot rate
Units: Percentage

Present Value of Cash Flows

PV=t=1nCFt(1+r)tPV = \sum_{t=1}^{n} \frac{CF_t}{(1 + r)^t}

This formula calculates the present value of a series of future cash flows, discounted back to the present time, applying the principle of cash flow additivity.

Variables:
PVPV:
Present value of the cash flows
CFtCF_t:
Cash flow at time t
rr:
Discount rate
tt:
Time period
nn:
Total number of periods
Units: Currency

Implied Return and Growth

Learning Outcome Statement:

calculate and interpret the implied return of fixed-income instruments and required return and implied growth of equity instruments given the present value (PV) and cash flows

Summary:

This LOS explores the concept of implied return and growth for both fixed-income and equity instruments. It explains how market expectations are reflected in the prices of these assets by solving for the implied return or growth rate using known present and future values. The content covers the calculation of yield-to-maturity (YTM) for fixed-income instruments and the relationship between required return, dividend yield, and growth for equities.

Key Concepts:

Implied Return for Fixed-Income Instruments

The implied return for fixed-income instruments like bonds can be calculated using the yield-to-maturity (YTM), which represents the internal rate of return (IRR) assuming all cash flows occur as scheduled. This is particularly straightforward for zero-coupon or discount bonds where the only cash flow is the payment at maturity.

Implied Return and Growth for Equity Instruments

For equity instruments, the implied return is the sum of the dividend yield and the growth rate of dividends. This is based on the assumption of constant growth in dividends. The required return on a stock can be derived from its current price, expected future dividends, and the growth rate of these dividends.

Price-to-Earnings Ratio

The price-to-earnings (P/E) ratio is a key metric in equity valuation, reflecting how much investors are willing to pay per dollar of earnings. The P/E ratio can be related to the required return and growth expectations through the dividend payout ratio and the growth rate of dividends.

Formulas:

Implied Return for Discount Bond

r=(FVPV)1t1r = \left(\frac{FV}{PV}\right)^{\frac{1}{t}} - 1

This formula calculates the annualized return for a discount bond over its life, assuming it is held to maturity.

Variables:
rr:
implied return
FVFV:
future value or bond principal at maturity
PVPV:
present value or price paid for the bond
tt:
number of periods until maturity
Units: percentage

Required Return for Equity

r=Dt+1PVt+gr = \frac{D_{t+1}}{PV_t} + g

This formula calculates the required return for a stock based on its expected dividend yield and growth rate.

Variables:
rr:
required return
Dt+1D_{t+1}:
dividend expected in the next period
PVtPV_t:
current price of the stock
gg:
constant growth rate of dividends
Units: percentage

Implied Growth Rate for Equity

g=rDt+1PVtg = r - \frac{D_{t+1}}{PV_t}

This formula calculates the implied growth rate of dividends for a stock based on its required return and expected dividend yield.

Variables:
gg:
implied growth rate
rr:
required return
Dt+1D_{t+1}:
dividend expected in the next period
PVtPV_t:
current price of the stock
Units: percentage

Time Value of Money in Fixed Income and Equity

Learning Outcome Statement:

calculate and interpret the present value (PV) of fixed-income and equity instruments based on expected future cash flows

Summary:

The Time Value of Money (TVM) in fixed income and equity involves understanding how the timing of cash flows affects the valuation of financial instruments. For fixed-income instruments like bonds, the present value is calculated based on expected future cash flows discounted at a rate that reflects the time value of money and risk. Equity instruments, such as stocks, are valued by discounting expected future dividends and growth rates. The concept also extends to calculating implied returns and growth rates from known present values and future cash flows.

Key Concepts:

Time Value of Money

The principle that money available at the present time is worth more than the same amount in the future due to its potential earning capacity.

Present Value (PV)

The current value of a future sum of money or stream of cash flows given a specified rate of return.

Future Value (FV)

The value of a current asset at a specified date in the future based on an assumed rate of growth over time.

Discount Rate (r)

The interest rate used to discount future cash flows of a financial instrument to present value.

Yield to Maturity (YTM)

The total return anticipated on a bond if the bond is held until it matures.

Perpetuity

A type of annuity that lasts forever, into perpetuity, providing a consistent flow of cash.

Annuity

A financial product that pays out a fixed stream of payments to an individual, primarily used as an income stream for retirees.

Coupon Bond

A bond that pays the holder a fixed interest payment (coupon payment) every year until the maturity date, when the principal amount is repaid.

Discount Bond

A bond bought at a price lower than its face value, with the face value repaid at maturity.

Formulas:

Future Value

FVt=PV(1+r)tFV_t = PV(1 + r)^t

Calculates the future value of a present sum after t periods at a periodic rate r.

Variables:
FVtFV_t:
Future value at time t
PVPV:
Present value
rr:
Discount rate per period
tt:
Number of compounding periods
Units: currency

Continuous Compounding Future Value

FVt=PVertFV_t = PVer^t

Calculates the future value with continuous compounding at a rate r over time t.

Variables:
FVtFV_t:
Future value at time t
PVPV:
Present value
rr:
Continuous compounding rate
tt:
Time in years
Units: currency

Present Value

PV=FVt(1+r)tPV = \frac{FV_t}{(1 + r)^t}

Calculates the present value of a future sum FV_t discounted back t periods at a rate r.

Variables:
PVPV:
Present value
FVtFV_t:
Future value at time t
rr:
Discount rate per period
tt:
Number of periods
Units: currency

Present Value of Perpetuity

PV=PMTrPV = \frac{PMT}{r}

Calculates the present value of a perpetuity, which is an infinite series of payments PMT, discounted at a rate r.

Variables:
PVPV:
Present value
PMTPMT:
Periodic payment
rr:
Discount rate per period
Units: currency

Present Value of Growing Perpetuity

PV=Dt+1rgPV = \frac{D_{t+1}}{r - g}

Calculates the present value of a perpetuity with dividends growing at a constant rate g.

Variables:
PVPV:
Present value
Dt+1D_{t+1}:
Dividend at time t+1
rr:
Required rate of return
gg:
Growth rate of dividend
Units: currency