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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.