Corporate Finance Basics

Finance is the discipline of allocating capital over time under uncertainty. Every business decision that commits resources has a financial structure: a cost, a benefit, a timing, and a risk. This skill catalogs the core techniques a manager or founder uses to evaluate investments, raise capital, and read financial statements — enough to make sound decisions without pretending to be a CFO.

Agent affinity: drucker (capital allocation and effectiveness), mintzberg (reading financials in context)

Concept IDs: bus-debt-vs-equity, bus-cost-benefit-analysis, bus-break-even-analysis, bus-investment-appraisal

The Finance Toolbox at a Glance

Technique 1 — Time Value of Money

Core principle. A dollar today is worth more than a dollar tomorrow, because the dollar today can be invested to earn a return, or simply because future dollars are less certain. The conversion is done with a discount rate $r$.

Formulas.

• Future value: $FV = PV \cdot (1 + r)^n$ where $PV$ is present value, $r$ is the periodic rate, $n$ is the number of periods.
• Present value: $PV = FV / (1 + r)^n$

Worked example. At $r = 8$ percent annual, $1000 received five years from now is worth $1000 / 1.08^5 = 1000 / 1.4693 \approx 680.58$ today. The opposite direction: $1000 invested today at 8 percent grows to $1469.33 in five years.

When it matters. Any decision where cash flows occur at different times must be time-adjusted. Comparing "save $500/year for 10 years" against "pay $3000 up-front" without discounting gives the wrong answer.

Technique 2 — Net Present Value (NPV)

Pattern: Sum the discounted cash flows of a project, including the initial investment as a negative at time zero. If NPV is positive, the project creates value at the chosen discount rate. If NPV is negative, it destroys value.

Formula.

$$NPV = \sum_{t=0}^{n} \frac{CF_t}{(1+r)^t}$$

Worked example. A project requires $100K today and produces $40K/year for 3 years. At $r = 10$ percent:

$$NPV = -100 + \frac{40}{1.1} + \frac{40}{1.1^2} + \frac{40}{1.1^3} = -100 + 36.36 + 33.06 + 30.05 = -0.53$$

Slightly negative. The project is not quite worth doing at a 10 percent cost of capital. At 8 percent the same project has NPV of +3.08 and is worth doing. The choice of discount rate is load-bearing.

Decision rule. Accept any project with positive NPV at the firm's cost of capital. Rank competing projects by NPV.

Technique 3 — Internal Rate of Return (IRR)

Pattern: The IRR is the discount rate that makes NPV equal to zero. It summarizes the project's return as a single annualized rate, comparable across projects.

Decision rule. Accept projects with IRR above the cost of capital. Reject below.

Limitations. IRR has three failure modes that NPV does not:

1. Non-unique IRRs — projects with non-conventional cash flows (e.g., negative cash flow in the middle) can have multiple valid IRRs.
2. Scale blindness — a 50 percent IRR on a $10K investment is worse than a 15 percent IRR on a $10M investment for most firms, but IRR ranks the smaller project higher.
3. Reinvestment assumption — IRR implicitly assumes intermediate cash flows are reinvested at the IRR itself, which is usually not achievable.

Rule of thumb. Use NPV for the decision; report IRR as a summary for communication.

Technique 4 — Payback Period

Pattern: The time required for cumulative cash inflows to equal the initial investment. A $100K investment producing $25K/year has a 4-year payback.

Strength. Simple, intuitive, and a reasonable proxy for liquidity risk — how long is capital locked up?

Weakness. Ignores time value of money and ignores cash flows after the payback threshold. A project with a 3-year payback and then zero return is ranked the same as one with a 3-year payback and then another decade of return.

When to use. As a screening filter before NPV. Payback is fast to compute and rules out obvious losers. Any project passing the payback screen still needs a full NPV before commitment.

Technique 5 — Break-even Analysis

Pattern: Find the volume at which total revenue equals total cost. Below break-even, the firm loses money; above, it profits. The formula separates fixed costs (independent of volume) from variable costs (proportional to volume).

Formula. $Q_{BE} = \frac{FC}{P - VC}$ where $Q_{BE}$ is break-even quantity, $FC$ is fixed costs, $P$ is price per unit, $VC$ is variable cost per unit, and $(P - VC)$ is the contribution margin.

Worked example. A product has $200K annual fixed cost, sells for $50, and costs $30 variable per unit. Break-even is $200{,}000 / (50 - 30) = 10{,}000$ units. If forecast demand is 8,000, the product loses money even at full execution. If forecast is 15,000, it produces a profit of $(15{,}000 - 10{,}000) \times 20 = 100{,}000$.

Strategic use. Break-even exposes whether a product concept can work at all, before any investment. A product whose break-even exceeds plausible demand is dead on paper.

Technique 6 — Cost-Benefit Analysis (CBA)

Pattern: Enumerate all costs and benefits of a decision (including non-monetary where possible), convert to dollars where feasible, and discount to present value. The decision rule is: proceed if benefits exceed costs in discounted terms.

Key disciplines.

• Enumerate both sides. Many CBAs fail by listing three costs and eight benefits, or by omitting opportunity cost (what else could this capital do?).
• Time-adjust. Costs now vs benefits in the future must be discounted.
• Handle uncertainty. Use ranges or expected values, not single-point estimates, when inputs are uncertain.
• Respect the uncommensurable. Some benefits (safety, reputation, mission fit) resist dollar conversion. Do not invent false precision; report them alongside the monetary calculation.

When NOT to use. When the core values at stake (safety of life, legal compliance, ethical commitments) are not negotiable, CBA can mislead by implying they are trade-offs. A safety decision is a constraint, not an input to a trade-off.

Technique 7 — Debt vs Equity

Pattern: When a firm needs capital, it can borrow (debt) or sell ownership (equity). Each has different costs, risks, and control implications.

Comparison.