Final methods · Side 1 of 2
rules · formulas · decisions
about QF5213
0 · Exam Mapcourse data · final mode 2026
“Open book but only hard copies.” (QF5213 course page (final test mode, 2026)) · “Examplify. Block internet. Open book.” (QF5213 course page (final test mode, 2026))
| Component | Weight | Format |
|---|---|---|
| Group Assignments | 20% | three submissions |
| Midterm Test | 40% | 2 h · MCQ · through Bonds |
| Final Test | 40% | 2 h · MCQ · all topics |
1 · Date Every Cash FlowC2 · core setup
single sumFVₜ = PV(1+r)ᵗ
PV = FVₜ/(1+r)ᵗ
uneven streamPV = Σ CFₜ/(1+r)ᵗ
Exam decision: moving right compounds; moving left discounts. For m compounding periods per year use r/m and mt together. Continuous: FV = PV·eʳᵗ.
| Prompt | Set-up | Check |
|---|---|---|
| amount due later | discount to t=0 | PV<FV for r>0 |
| deposit today | compound to target date | FV>PV for r>0 |
| uneven stream | PV every signed flow separately | all terms share one date |
| monthly/semiannual | divide rate; multiply periods | units match |
Why time has value: current money can earn interest, inflation reduces future purchasing power, and promised payment may fail. Simple interest adds the same dollar amount each period; compound interest earns on accumulated interest. More frequent positive compounding raises FV but lowers the PV needed to reach a fixed future amount.
Independent check: value an uneven stream at t=0, then compound that total to the final date. It must match compounding each individual flow to that date. A one-period counting error breaks this equality.
Goal and control · C1
2 · Level StreamsC3 · formula choice
ordinary annuityPV = C[1−(1+r)⁻ⁿ]/r
FV = C[(1+r)ⁿ−1]/r
annuity duePV or FV = ordinary value × (1+r)
perpetuitieslevel: PV = C/r
growing: PV = C₁/(r−g), requiring g<r
Trigger words: “end”, “next month/year” → ordinary; “today”, “immediately”, “beginning” → due. A deferred perpetuity is first valued one period before its first payment, then discounted to today.
| Unknown | Rearrange / interpretation |
|---|---|
| loan payment C | C = PV ÷ annuity factor |
| savings target | C = FV ÷ FV annuity factor |
| balance after k payments | PV at k of remaining instalments |
| due stream | ordinary value ×(1+r) |
Amortisation: each instalment splits into interest = opening balance×period rate and principal = payment−interest; new balance = old balance−principal. Early instalments carry more interest because the balance is larger.
3 · Make Rate Match PaymentC3 · APR/EAR
EAR = (1 + APR/m)ᵐ − 1
payment-period r = (1+EAR)¹ᐟᵏ − 1
| Basis | What earns interest | Implication |
|---|---|---|
| Reducing balance | balance still owed | quote and true period rate align |
| Flat | original principal throughout | true cost much higher |
| Annual rest | balance reset yearly | between the two |
4 · Appraisal Rule HierarchyC4 · decision marks
net present valueNPV = CF₀ + Σₜ₌₁ⁿ CFₜ/(1+r)ᵗ
accept independent project if NPV>0
return and scarcityIRR solves NPV=0; accept conventional project if IRR>r
PI = PV(inflows)/initial outlay; accept if PI>1
| Method | Use | Failure mode |
|---|---|---|
| NPV | dollars of value | forecast/rate quality |
| IRR | percentage return | ranking conflict; multiple roots |
| PI | benefit per $ under a cap | not the unconstrained rank |
| Payback | liquidity speed | ignores later CFs; simple form ignores TVM |
Ranking conflict: for mutually exclusive projects, use the higher NPV. Find crossover as IRR of year-by-year differences. More than one sign change can produce multiple IRRs: report the range where NPV>0. Unequal lives, if repeatable: common life or EAA = NPV/annuity factor.
What each edge case asks
Independent projects: accept every NPV>0 project if funds are available. Mutually exclusive: selecting one removes the other, so dollar value wins. Capital rationing: rank benefit per constrained dollar with PI, then choose the feasible bundle that maximises total NPV. Unequal lives: use EAA/common life only if repetition is realistic; otherwise compare ordinary NPVs.
hurdle from financing mixWACC = w_d r_d(1−T) + w_e r_e
Multiple-IRR diagnostic: −10,000, +26,000, −16,500 changes sign twice and has IRRs of 10% and 50%; NPV is positive only between them (at 25%, +240). State the acceptable rate band, not one misleading IRR.
Payback interpolation: full years before recovery + unrecovered amount at start of recovery year / that year's cash flow. Discounted payback uses present values first. Both ignore every flow after recovery and depend on an arbitrary cutoff.
5 · Build the Project Cash FlowC5 · classification core
operating cash flowOCF = (Revenue−cash costs)(1−T) + T·Dep
after-tax salvageATSV = SV − T(SV−BV)
| Item | Rule |
|---|---|
| Sunk cost | exclude: occurs either way |
| Opportunity cost | include best forgone use |
| Erosion / complements | include induced loss / gain |
| Allocated overhead | only the incremental part |
| Interest / dividends | exclude: WACC already prices financing |
| Net working capital | outflow when tied up; inflow on release |
| Depreciation | not cash; include its tax shield |
Exam test: would this cash move if the project were rejected? If no, include it; if yes anyway, exclude it; if only part changes, include only that increment. Below-book salvage makes (SV−BV) negative, so the formula adds a tax credit.
Three-block assembly
CF₀ = −(asset price + freight + installation) − ΔNWC₀
CFₜ = OCFₜ − later capital spending − ΔNWCₜ
CFₙ adds ATSV + release of NWC
Two equivalent OCF routes: from cash margin, use (R−cash costs)(1−T)+T·Dep; from operating profit after tax, add depreciation back. Do not add both the full depreciation and its shield. Credit sales enter cash flow when collection occurs, not merely when accounting revenue is booked.
Classification traps: research paid last year is sunk even if it feels project-related; rent forgone on owned space is an opportunity cost only if an alternative tenant/use exists; cannibalised contribution is charged only when the launch causes it; extra complementary sales are credited; a shared overhead allocation is excluded unless total firm cash overhead changes.
6 · Risk Around the Base NPVC6 · analysis
NPV response ratio = %ΔNPV / %Δinput
break-even volumeAccounting Q = (fixed cost + depreciation)/(price−variable cost)
EAC = initial outlay / annuity factor
Financial Q = [EAC + fixed(1−T) − T·Dep] / [(price−variable)(1−T)]
Accounting break-even sets profit=0; tax cancels. Financial break-even sets NPV=0 and charges the required return, so it is higher whenever r>0. Compare expected volume with the correct line and state the safety margin.
| Tool | Change | Answer |
|---|---|---|
| Sensitivity | one input; rest fixed | which forecast drives NPV? |
| Scenario | linked inputs together | what does a coherent state do? |
| Break-even | solve sales/volume | where does profit or NPV reach zero? |
Course plant: price $2,600→$2,450 moves NPV $15.77m→−$10.31m; response ≈28.7% of NPV per 1% price change. Research the longest bar first.
7 · Trees & FlexibilityC7 · fold back
option value = NPV with flexibility − NPV without flexibility
| Delay | compare every launch-date NPV after discounting it to today |
| Abandon | take salvage when it beats continuing |
| Expand | scale a successful branch without scaling the failed one |
8 · Common StockC8 · valuation
required return: rₛ = r_f + β(market risk premium)
zero growth: P₀ = D₁/rₛ
constant growth: P₀ = D₁/(rₛ−g), g<rₛ
two-stage: P₀ = Σ Dₜ/(1+rₛ)ᵗ + Pₙ/(1+rₛ)ⁿ
Pₙ = Dₙ₊₁/(rₛ−g)
| Method | Use / bridge |
|---|---|
| P/E | positive, meaningful earnings |
| P/S | loss-making firm; revenue positive |
| P/B | market price against net assets |
| EV/EBITDA | enterprise value → + excess cash − debt → equity; ÷ shares |
| Free cash flow | discount at WACC → same enterprise-to-equity bridge |
Trap: the growth model uses D₁, not D₀. A takeover premium over the last trade is not proof of fairness; compare with an independent intrinsic value.
Price directions: higher risk-free rate, beta or market premium raises rₛ and lowers price; stronger dividends or sustainable growth raises price. Never force g≥rₛ into the constant-growth formula.
9 · BondsC9 · pricing/yields
Price = C[1−(1+y)⁻ⁿ]/y + F/(1+y)ⁿ
current yield = annual coupon / price
| Position | Rate order |
|---|---|
| Premium | coupon rate > current yield > YTM |
| Par | coupon rate = current yield = YTM |
| Discount | coupon rate < current yield < YTM |
Semiannual: n=2×years; C=annual coupon/2; y=quoted YTM/2. Calculator RATE returns the half-year rate; double for quoted YTM, compound for EAR. Long maturity/small coupon → greater price risk; short maturity/large coupon → greater reinvestment risk.