Formulas and definitions.

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50 matching entries

Build a balance sheet

Borrowing increases cash and debt by the same amount. Equity is the residual claim after liabilities.

Assets = Liabilities + Equity
Every asset is funded by a creditor or an owner. Subtract liabilities from assets to get equity. In the example, ₹80,000 − ₹50,000 = ₹30,000.

A café has ₹80,000 in assets and ₹50,000 of liabilities. Equity is ₹30,000.

Common mistake. Cash from a loan is a financing inflow. It does not enter revenue or profit.

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Price elasticity

Elasticity compares the percentage change in demand with the percentage change in price.

Midpoint elasticity = (ΔQ / average Q) ÷ (ΔP / average P)
ΔQ and ΔP are signed changes in quantity and price. Divide each change by its two-point average. (−20 ÷ 90) ÷ (₹10 ÷ ₹105) ≈ −2.33. The units cancel.

At ₹100 you sell 100 tickets. At ₹110 you sell 80. The midpoint elasticity is about −2.33.

Common mistake. A steep line on a chart is not an elasticity estimate without knowing its units and the baseline.

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Expected value

Expected value weights every possible outcome by its probability.

E[X] = Σ probability × outcome
Σ means add the probability-weighted outcomes. Treat losses as negative. 0.60 × ₹100 + 0.40 × (−₹50) = ₹40.

A 60% chance of ₹100 and a 40% chance of losing ₹50 yields an expected ₹40.

Common mistake. Expected profit does not tell you whether you can survive the loss scenario.

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Net present value

Discount future cash flows into today’s money, then subtract the investment.

NPV = CF₀ + Σ CFₜ / (1 + r)ᵗ
CF₀ is the cash flow today, CFₜ is the cash flow at the end of period t, and r is the discount rate per period. −₹100,000 + ₹120,000 ÷ 1.10 = ₹9,090.91.

At 10%, ₹120,000 next year is worth ₹109,090.91 today. Subtract ₹100,000 to get ₹9,090.91.

Common mistake. Subtract sunk costs only if they are still avoidable. A payment already made is outside the incremental decision.

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Break-even volume

Every sale contributes its price minus variable cost toward fixed costs.

Break-even units = fixed cost ÷ (unit price − variable cost)
Every unit contributes its price less variable cost. ₹60,000 ÷ (₹500 − ₹300) = 300 units. If contribution is zero or negative, more units cannot cover positive fixed costs.

₹60,000 fixed cost, ₹500 price and ₹300 variable cost give 300 units.

Common mistake. Using revenue per unit as the denominator ignores the cost of making each additional unit.

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Profit versus cash

A sale can count as revenue before the customer pays. Inventory can use cash before it becomes an expense.

Operating cash flow ≈ profit + noncash charges − increase in operating working capital
Begin with profit, reverse noncash charges, then remove cash tied up in operating working capital. ₹100 + ₹20 − ₹60 = ₹60 here.

₹100 profit plus ₹20 depreciation minus ₹60 more receivables yields ₹60 cash flow, holding other items constant.

Common mistake. Comparing profit to cash flow without checking working capital can misdiagnose the business.

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Marginal and effective tax

In a simple graduated system, each rate applies to the slice of taxable income in that bracket.

Effective rate = total tax ÷ taxable income
The effective rate spreads the total liability across all taxable income. In this fictional schedule, tax is 10% × ₹50,000 = ₹5,000, then ₹5,000 ÷ ₹150,000 ≈ 3.33%.

In a fictional schedule, the first ₹100,000 is exempt and the next slice taxed at 10%. At ₹150,000, liability is ₹5,000, or 3.33%.

Common mistake. Applying the top bracket to all income overstates liability in a simple slice-based schedule.

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Diversification

Portfolio risk depends on how assets move together as well as their individual volatility.

σₚ² = w₁²σ₁² + w₂²σ₂² + 2w₁w₂σ₁σ₂ρ
w is a portfolio weight, σ is volatility, and ρ is the correlation between returns. With 50/50 weights and zero correlation, variance is 2 × (0.5 × 0.20)² = 0.02. Take the square root to get 14.14%.

Two equally weighted 20%-volatility assets with zero correlation give about 14.14% portfolio volatility.

Common mistake. Diversification may weaken when correlations rise under stress.

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Price a bond

Higher yields discount fixed future payments more heavily.

Price = Σ coupon / (1 + y)ᵗ + face / (1 + y)ⁿ
Discount each coupon and the final principal at the market yield y. The one-year payment is $1,000 + $50 = $1,050, which is $954.55 today at a 10% yield.

A one-year $1,000 bond with a 5% coupon is worth $1,050 ÷ 1.10 = $954.55 at a 10% yield.

Common mistake. Coupon rate sets the contractual payment. Market yield changes the price.

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Call option payoff

A call gives its buyer the right to buy at the strike. Profit at expiry subtracts the premium.

Expiry profit = max(spot − strike, 0) − premium
The buyer can walk away if spot is below strike. At $104, the right to buy for $100 pays $4. The $6 premium turns the payoff into a $2 loss.

With strike $100 and premium $6, a spot of $104 yields a $4 payoff and a $2 loss.

Common mistake. Confusing the strike with the buyer’s break-even price overlooks the premium.

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Real returns

Real return measures purchasing power. Nominal return measures currency growth.

Real return = (1 + nominal return) / (1 + inflation) − 1
Divide the money growth factor by the price growth factor. 1.08 ÷ 1.05 − 1 ≈ 2.86%, the growth in purchasing power.

An 8% return with 5% inflation produces about 2.86% real growth.

Common mistake. Subtracting inflation is an approximation that gets less accurate at larger rates.

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Anchoring

Anchoring gives an initial number more influence than the evidence warrants.

Compare a fresh estimate with the quoted reference point.
₹100 and ₹60 are historical and current prices. The ₹45 estimate comes from a separate cash-flow forecast. Compare the model with the prices only after writing down its assumptions.

A stock fell from ₹100 to ₹60. Revised cash flows imply ₹45 under your assumptions.

Common mistake. Calling a stock cheap because it fell ignores the change in fundamentals.

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Hedge a currency payable

An importer who owes dollars loses purchasing power when USD costs more INR. A forward can fix the INR cost.

INR cost = USD payable × INR per USD
Multiply the dollar invoice by rupees per dollar. $10,000 × ₹84/USD = ₹840,000. USD cancels, leaving INR.

A $10,000 payable at a forward rate of ₹84/USD costs ₹840,000 under the contract.

Common mistake. A hedge should match the exposure direction. Selling dollars forward would add risk to this payable.

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Value at risk

Value at risk estimates a loss threshold at a specified horizon and confidence level.

VaR at level α = α-quantile of modeled losses
At a 95% confidence level, order the modeled losses and find their 95th percentile. The ₹100,000 threshold describes a loss quantile. It leaves the size of more extreme losses unspecified.

A model with 95% VaR of ₹100,000 gives a threshold, not a bound on possible loss.

Common mistake. Treating VaR as maximum possible loss hides extreme outcomes.

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Build a DCF

Forecast free cash flow, discount it, then estimate what remains beyond the explicit forecast.

EV = Σ FCFFₜ / (1 + WACC)ᵗ + [FCFFₙ × (1 + g) / (WACC − g)] / (1 + WACC)ⁿ
FCFF is cash flow available to all capital providers, WACC is the discount rate and g is perpetual growth. Discount each forecast cash flow and the terminal value separately. With level cash flow forever, $10m ÷ 10% = $100m.

With $10m cash flow in year one, WACC 10% and zero growth forever, EV is $100m.

Common mistake. Putting interest expense in FCFF mixes equity financing with a firm-level discount rate.

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Enterprise and equity value

Enterprise value approximates the value of operating assets. Equity value belongs to shareholders.

Enterprise value = equity value + debt − excess cash
Begin with what shareholders receive. Add debt and subtract cash available above operating needs. $60m + $18m − $8m = $70m.

At $60m equity, $18m debt and $8m cash, EV is $70m.

Common mistake. Subtracting operating cash that the business needs can understate the acquisition cost.

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Model a leveraged buyout

Borrowing reduces entry equity. Remaining debt reduces what shareholders receive at exit.

MOIC = exit equity ÷ entry equity; annual return = MOIC^(1/years) − 1
Entry equity is $100m − $60m = $40m. Exit equity is $120m − $40m = $80m. That is 2×. Take the holding-period root to annualize a single exit payment.

Buy for $100m with $60m debt. Exit at $120m EV with $40m debt remaining. $80m proceeds on $40m equity gives 2×.

Common mistake. Lower entry equity amplifies losses as well as gains. Fees and interim distributions are excluded here.

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Value acquisition synergies

Synergy creates value only if the incremental benefit exceeds the premium and integration costs.

Acquirer value gain ≈ PV of net synergies − premium over standalone value
Start with the value of savings or extra profits, subtract integration costs, then subtract what the buyer paid above standalone value. $20m − $8m − $15m = −$3m.

$20m of gross synergy PV less $8m of integration costs and a $15m premium implies −$3m for the acquirer.

Common mistake. A recurring savings run rate is not the same as its risk-adjusted present value.

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Trading comparables

Comparable companies offer valuation anchors when their economics and metrics are aligned.

Implied EV = selected peer EV/EBITDA × normalized target EBITDA
A multiple says how much operating value investors pay per unit of normalized earnings. 8× × $9m = $72m. Match the earnings period and accounting basis across peers.

At 8× and $9m normalized EBITDA, implied EV is $72m.

Common mistake. A median is only as informative as its peer group. Negative EBITDA makes the multiple hard to interpret.

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Debt service coverage

Coverage tests cash available for debt service against scheduled interest and principal.

DSCR = cash available for debt service ÷ scheduled debt service
Compare cash available during the period with scheduled interest plus principal for the same period. ₹120 crore ÷ ₹100 crore = 1.20×.

₹120 crore available against ₹100 crore of principal and interest gives 1.20×.

Common mistake. EBITDA can ignore tax, maintenance capital and working capital required to produce available cash.

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Expected credit loss

Loss depends on whether a borrower defaults, how much is exposed, and how much can be recovered.

Illustrative expected loss = PD × LGD × EAD
PD is probability of default, LGD is loss as a share of exposure if default occurs, and EAD is exposure at default. 0.02 × 0.40 × ₹1 crore = ₹80,000 in this one-period example.

2% default probability × 40% loss severity × ₹1 crore exposure gives ₹80,000.

Common mistake. Expected loss is a portfolio planning estimate. It is distinct from a single borrower’s realized loss.

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Payments reconciliation

Authorization, clearing and settlement answer different questions. Reconciliation matches internal records to external movements.

Net settlement = gross settled payments − fees − applicable reversals
Start with transactions settled in the same batch, then subtract separately reported fees and reversals. ₹10,000 − ₹150 − ₹350 = ₹9,500.

₹10,000 in settled sales minus ₹150 fees and a ₹350 refund yields ₹9,500.

Common mistake. Retrying an uncertain payment without idempotency can create a duplicate charge.

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Replicate a derivative payoff

If two portfolios produce the same payoff in every modeled state, no-arbitrage gives them the same price under the model assumptions.

Delta = (up payoff − down payoff) ÷ (up stock price − down stock price)
The option payoff rises $20 between states while the stock rises $40. Hold $20 ÷ $40 = 0.5 shares, then use borrowing to match the payoff level in both states.

Stock moves to $120 or $80. A $100-strike call pays $20 or $0. Replication uses 0.5 shares and debt with $40 due at expiry.

Common mistake. Delta depends on the modeled states and changes as time and spot move.

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Interpret carbon intensity

Carbon intensity divides emissions by a measure such as output or revenue. Absolute emissions measure total volume.

Intensity = tonnes of CO₂e ÷ activity measure
Divide total emissions by output. 110 tonnes ÷ 125 units = 0.88 tonnes per unit. Total emissions rose even though emissions per unit fell.

Emissions increase from 100 to 110 tonnes while production rises from 100 to 125 units. Intensity falls from 1.00 to 0.88 tonnes per unit.

Common mistake. Presenting an intensity decline as an absolute emissions reduction can mislead investors.

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Earned, billed and collected

Under accrual accounting, revenue follows the work performed. Cash collection settles the claim and can happen later.

Ending receivable = earned revenue − collections on that revenue
March earned ₹24,000 and collected ₹15,000 on that service. The ₹9,000 difference is an asset. Collecting it later swaps receivable for cash.

Record ₹24,000 of March revenue. Collect ₹15,000 and leave ₹9,000 in receivables. April collection of the balance raises cash by ₹9,000 and lowers receivables by the same amount.

Common mistake. Adding April collections to April revenue would count the same service twice. Receiving cash before performing a service would be a different case, generally involving a liability.

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Find market equilibrium

Equilibrium is where quantity demanded matches quantity supplied. A shift in the whole demand curve changes that crossing.

If Qd = a − 2P and Qs = b + 3P, then P* = (a − b) ÷ 5
Set 100 − 2P equal to 20 + 3P. Rearrange to 80 = 5P, so P is ₹16. Put ₹16 into either curve to get 68 units.

With a = 100 and b = 20, price is ₹16. Both curves give 68 units. At ₹10, buyers want 80 units and sellers offer 50, leaving a shortage of 30.

Common mistake. Higher demand means more buying at the same price. Moving along an unchanged demand curve is a response to price, a different event.

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Bayes and default flags

Compare true and false alerts in the population. When defaults are uncommon, false alerts can outnumber true ones.

P(D|F) = P(D)P(F|D) ÷ [P(D)P(F|D) + P(not D)P(F|not D)]
Out of 1,000 borrowers, 50 × 80% gives 40 true flags and 950 × 10% gives 95 false flags. Divide 40 by the 135 total flags.

Of 1,000 similar borrowers, expect 50 defaults at a 5% base rate. At 80% sensitivity, expect 40 true flags. At a 10% false-positive rate, expect 95 false flags. The share of flagged borrowers expected to default is 40 ÷ 135 ≈ 29.63%.

Common mistake. Reading sensitivity as the probability of default after a flag reverses the conditioning.

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Estimate the cost of capital

A project funded by a mix of debt and equity must earn enough to compensate both groups. WACC combines their required returns.

WACC = equity weight × cost of equity + debt weight × cost of debt × (1 − tax rate)
E and D are fractions of total market-value funding. Multiply 0.60 × 12%, then add 0.40 × 8% × (1 − 0.25). The result is 9.6%.

60% equity at 12%, 40% debt at 8% and a hypothetical 25% tax rate give 7.2% + 2.4% = 9.6%.

Common mistake. Using book weights or applying one corporate discount rate to unrelated project risks can distort a valuation.

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Diagnose return on equity

DuPont analysis decomposes return on equity into profit margin, asset turnover and the equity multiplier.

ROE = net income ÷ sales × sales ÷ average assets × average assets ÷ average equity
Cancel sales and average assets from the middle terms to get net income divided by average equity. 8% × 1.25 × 2 = 20%.

Sales ₹200 lakh, net income ₹16 lakh, average assets ₹160 lakh and average equity ₹80 lakh. 8% margin × 1.25 asset turnover × 2 equity multiplier = 20% ROE.

Common mistake. Calling a higher ROE an operating improvement without checking margin, turnover and leverage separately.

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Estimate bond rate sensitivity

Modified duration estimates the percentage price change for a small yield change. A five-year duration gives roughly a 5% move for a one-point yield change.

Modified duration = Macaulay duration ÷ (1 + yield); Δprice / price ≈ −duration × Δyield
For a zero-coupon bond, the only cash flow arrives at year five. Modified duration is 5 ÷ 1.05 ≈ 4.76 years. Multiply by −0.005 for an approximate 2.38% loss.

A five-year zero at 5% yield has modified duration 5 ÷ 1.05 ≈ 4.76 years. A 0.50-point yield rise gives an approximate 2.38% price decline.

Common mistake. Enter a 50 basis point move as 0.005 in the formula, not 0.50.

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From beta to required return

CAPM adds compensation for exposure to broad market movements to the risk-free rate.

Cost of equity = risk-free rate + beta × market risk premium
Beta 1.2 scales the 5% market premium to 6 percentage points. Add the 4% risk-free rate to obtain 10%.

At a 4% risk-free rate, beta 1.2 and a 5% market risk premium, cost of equity is 4% + 1.2 × 5% = 10%.

Common mistake. Substituting the full market return for the market risk premium double-counts the risk-free component.

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Model debt paydown and exit equity

A cash sweep uses available cash to repay debt before exit. Less debt at sale means a larger residual for shareholders, holding operating value and other claims fixed.

Ending debt = max(opening debt − cash swept, 0); exit equity = max(exit EV − ending debt, 0)
Repay up to $10m in each of three years. The $60m balance falls to $30m. Exit equity is $120m − $30m = $90m, before any fees.

Buy at $100m EV with $60m debt and $40m sponsor equity. Sweep $10m annually for three years. Exit debt falls to $30m. At $120m exit EV, equity receives $90m, equal to 2.25× invested capital.

Common mistake. Subtracting interest again from a cash flow already defined after interest would understate sweep capacity. Using a constant cash flow also hides the effect of lower debt on later interest.

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Size debt service to a covenant

A coverage covenant requires cash available to exceed scheduled debt service by a stated factor. Work backward from the covenant to size the maximum payment.

Debt service ceiling = cash available for debt service ÷ target DSCR
Scheduled principal and interest together can be at most ₹108 crore ÷ 1.20 = ₹90 crore for the period. This is a service ceiling, not a debt balance.

At ₹108 crore available cash and a 1.20× minimum coverage ratio, the payment ceiling is ₹90 crore. A proposed payment of ₹100 crore needs a ₹10 crore reduction in that period.

Common mistake. Using gross revenue in place of cash available overstates capacity. Averaging the ratio across periods can hide a breach in a single period.

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Explain deferred tax timing

Different depreciation schedules can shift the timing of tax. An earlier tax deduction can create a deferred tax liability.

Deferred tax liability = taxable temporary difference × assumed tax rate
₹80 lakh − ₹60 lakh = ₹20 lakh taxable difference. Multiply by 0.25 to get ₹5 lakh.

A machine’s carrying amount is ₹80 lakh and tax base is ₹60 lakh. At 25%, the ₹20 lakh difference gives a ₹5 lakh liability.

Common mistake. Tax expense and tax paid can diverge. A temporary difference is expected to reverse, whereas a permanent difference does not reverse.

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Check the base rate before reacting

Start with the frequency in a relevant comparison group, then update when new evidence distinguishes this case.

Observed base rate = comparable successes ÷ comparable observations
4 ÷ 20 = 20%. It describes the chosen historical sample and is only a starting point.

Four of 20 comparable firms refinanced within six months. Start with 20% as a descriptive rate before investigating the new borrower.

Common mistake. Counting only firms still listed after six months omits failures and can inflate the historical success rate.

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Translate a stress scenario into loss

Apply a coherent adverse scenario to each position and combine signed impacts. A stress test estimates severity under the scenario.

Scenario P&L ≈ sum of signed position impacts
Put all impacts on a signed basis: −6 − 9 + 4 = −11, in ₹ lakh.

A currency move costs ₹6 lakh and a bond position loses ₹9 lakh. Combined P&L is −₹15 lakh before liquidity effects.

Common mistake. Adding magnitudes can overstate loss if a position gains. Retain signs and evaluate basis and liquidity separately.

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Backtest a VaR model

An exception occurs when realized loss exceeds the forecast threshold. Compare frequency and clustering over a defined window.

Expected exceptions = number of observations × (1 − confidence level)
250 × (1 − 0.99) = 2.5 expected exceptions. Five observed is 5 ÷ 250 = 2%.

Over 250 days, a 99% model expects 2.5 exceptions. Five observed exceptions imply an observed rate of 2%, which merits investigation.

Common mistake. Expected count is an average across samples, not an automatic pass/fail rule for one sample.

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Calculate EPS accretion and dilution

Compare the buyer’s earnings per share before and after the deal. Accretion measures the change in this ratio, while value depends on what you pay and earn.

EPS change = pro forma EPS ÷ standalone EPS − 1
Standalone $60m ÷ 30m = $2. Pro forma $75m ÷ 35m ≈ $2.142857. Divide by $2 and subtract one for about 7.14%.

Buyer has $60m earnings and 30m shares, so EPS is $2. Add $12m target earnings and $3m synergy, with 5m new shares. $75m ÷ 35m ≈ $2.14, or 7.14% accretion.

Common mistake. EPS accretion can come from relative multiples or accounting. It does not establish positive NPV.

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Separate primary and secondary IPO proceeds

Primary shares raise money for the issuer. Secondary shares transfer proceeds to selling holders.

Issuer net proceeds = offer price × newly issued shares − issuer offering costs
New shares raise $80m for the issuer before costs; $40m from existing shares goes to sellers before their costs. Issuer net is $80m − $5m.

At $20, 4m new shares and 2m existing shares produce a $120m gross offering. With $5m issuer costs, the company receives $75m net.

Common mistake. Using total deal size as issuer cash raised treats selling holders’ proceeds as company funds.

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Measure payment funnel economics

Measure each stage on a consistent cohort. Approval improvements only add value when payments reach capture and settlement.

End-to-end settlement rate = settled transactions ÷ eligible checkout attempts
9,000 ÷ 10,000 = 90% approval and 8,550 ÷ 9,000 = 95% post-approval settlement. Multiply for 85.5%.

Of 10,000 attempts, 9,000 are approved. Of those, 8,550 are captured and settle. End-to-end rate is 85.5%.

Common mistake. A rise in approval rate can hide a drop in later-stage conversion or an increase in fraud.

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Price a call in a two-state tree

In a one-step arbitrage-free tree, use a pricing weight that makes the expected stock value grow at the risk-free rate.

q = (S × R − Sd) ÷ (Su − Sd); call = (q × up payoff + (1 − q) × down payoff) ÷ R
(105 − 80) ÷ (120 − 80) = 0.625. Payoffs are $20 and $0. Discount $12.50 by 1.05 for about $11.90.

Stock is $100, up is $120, down is $80, strike is $100 and R = 1.05. q is 0.625. Call value is $12.50 ÷ 1.05 ≈ $11.90.

Common mistake. Substituting a subjective up probability into this formula loses the replication argument.

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Make or buy a component

Compare costs that change with the decision. Allocated overhead can remain even if production stops.

Advantage of buying = avoidable production cost + opportunity benefit − purchase cost
₹77 × 10,000 avoided + ₹120,000 contribution − ₹84 × 10,000 paid = ₹50,000.

Buying changes cost by ₹84 − ₹77 = ₹7 per part, or ₹70,000 more overall. Keep making under these assumptions.

Common mistake. Counting all allocated fixed costs as savings overstates the benefit of outsourcing.

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Measure the cash conversion cycle

Add inventory days and collection days, then subtract supplier payment days.

Cash conversion cycle = inventory days + receivable days − payable days
45 inventory days + 38 collection days − 30 supplier days = 53 days.

A distributor holds stock for 45 days, collects in 38 and pays suppliers in 30. The cycle is 53 days.

Common mistake. Do not infer the funding amount from days alone. Convert each component with its own daily flow.

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Bridge operating profit to free cash flow

Start with operating profit after assumed tax. Add noncash depreciation and deduct investment in equipment and working capital.

FCFF = EBIT × (1 − tax rate) + depreciation − capex − increase in operating working capital
$40m × 75% = $30m after operating tax. $30m + $6m − $12m − $4m = $20m.

EBIT is $40m and assumed tax is 25%. Add $6m depreciation, subtract $12m capex and $4m more working capital. FCFF is $20m.

Common mistake. Subtracting interest mixes operating cash flow with financing cash flow.

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Stress-test terminal value

Terminal value estimates cash flows beyond the explicit forecast. A small discount-rate-minus-growth spread magnifies assumptions.

Terminal value at year n = FCFF in year n + 1 ÷ (WACC − growth)
$8m ÷ (10% − 2%) = $100m at year five. $100m ÷ 1.10⁵ ≈ $62.09m today.

Year-six FCFF is $8m, WACC is 10% and growth is 2%. At year five, terminal value is $100m. Discounting five years gives about $62.09m today.

Common mistake. Using the last forecast year’s cash flow without converting to the following year shifts the timing.

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Protect a share position with a put

A put gives the holder the right to sell at a strike price. The protection costs a premium.

Expiry P&L = spot + max(strike − spot, 0) − initial share price − premium
At $82, the put is worth $13. $82 + $13 − $100 − $3 = −$8.

Buy the share for $100 and a $95 put for $3. At expiry spot of $82, the share and put together are worth $95, leaving an $8 loss.

Common mistake. The strike is the floor for expiry proceeds. The premium must still be included in total profit and loss.

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Model compound growth

Compounding earns a return on the original balance and on returns already retained.

Future value = principal × (1 + periodic return) raised to the number of periods
₹50,000 × 1.08 × 1.08 = ₹58,320. The second 8% applies to ₹54,000.

₹50,000 at 8% annually becomes ₹54,000 after one year and ₹58,320 after two. Year two adds ₹4,320.

Common mistake. Adding 8% of the original principal each year models simple interest.

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Read a bank’s net interest margin

Funding costs can rise faster than interest income. Margin tracks the net interest earned on the average earning asset base.

Net interest margin = (interest income − interest expense) ÷ average interest-earning assets
(₹92 crore − ₹48 crore) ÷ ₹1,100 crore = 4.0%.

A fictional bank earns ₹92 crore interest and pays ₹48 crore over a year, with ₹1,100 crore average earning assets. NIM is 4.0%.

Common mistake. Dividing by total closing assets instead of average earning assets changes the measure.

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Read a regression slope

A regression slope summarizes association in the fitted data. It does not by itself identify an intervention’s effect.

Slope = sum of centered x × centered y ÷ sum of squared centered x
The centered x values are −1, 0, 1, so the cross-product sum is 13 − 7 = 6. Divide by 1 + 0 + 1 = 2.

Advertising values are 1, 2 and 3 lakh and sales are 7, 9 and 13 lakh. The centered cross-product sum is 6 and the centered squared x sum is 2. Slope is 3.

Common mistake. The slope has units. Here it is lakh of fitted sales per lakh of advertising.

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Price a sustainability-linked coupon step

A sustainability-linked bond can change its coupon if a defined performance target is missed. Read the contract before counting cash flows.

Annual incremental interest = principal × step-up in basis points ÷ 10,000
₹200 crore × 25 ÷ 10,000 = ₹0.50 crore per affected year.

On ₹200 crore principal, a 25 basis-point step adds ₹0.50 crore per affected year. A 7.00% coupon becomes 7.25%.

Common mistake. Do not apply the step-up to years before the contract activates it.

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