Three-Statement Modeling

This is, honestly, the single most commonly failed technical question in real banking interviews — not because it's conceptually hard, but because most candidates have only ever seen the three statements separately, never watched them actually move together. This lesson builds the linkage by hand, with one concrete example, rather than just stating the rules.

The three statements, in one sentence each

• Income statement: how much money the company made this period (revenue down to net income) — a flow over time.
• Balance sheet: what the company owns and owes at one specific moment — a snapshot, not a flow.
• Cash flow statement: where the company's actual cash came from and went during the period — because net income (an accounting figure, full of non-cash items and timing assumptions) is not the same thing as cash in the bank.

The classic interview question: "Walk me through what happens to the three statements if depreciation increases by $10"

This is close to the single most common technical question asked in real interviews, precisely because answering it correctly requires you to actually understand the linkage, not just recite definitions. Walk through it slowly:

1. Income statement: Depreciation is an operating expense, so a $10 increase in depreciation reduces operating income (EBIT) by $10. Assume a 25% tax rate: pre-tax income falls by $10, so taxes owed fall by $10 × 25% = $2.50. Net income therefore falls by $10 − $2.50 = $7.50.

2. Cash flow statement: Start with net income (down $7.50). But depreciation is a non-cash expense — the company didn't actually pay out $10 in cash, it just recognized an accounting charge for an asset wearing out. So on the cash flow statement, you add depreciation back: −$7.50 (net income) + $10 (add back depreciation) = cash flow from operations is actually UP $2.50. This is the single most counter-intuitive, most-tested part of the whole exercise: an expense that reduces accounting profit can increase real cash — because the tax savings from that non-cash deduction ($2.50) is real cash the company didn't have to pay to the government.

3. Balance sheet: Cash is up $2.50 (from the cash flow statement above) → assets side up $2.50. Accumulated depreciation is up $10, which reduces net PP&E (property, plant & equipment) by $10 → assets side down $10 from this. Net effect on assets: +$2.50 − $10 = down $7.50. On the other side: retained earnings (part of equity) falls by the $7.50 drop in net income → equity down $7.50. Assets down $7.50, liabilities+equity down $7.50 — the balance sheet still balances. That's the whole test, and the reason this question gets asked: if your walk-through doesn't end with the balance sheet actually balancing, something in your logic was wrong.

Why this matters more than memorizing the mechanic

An interviewer doesn't actually care whether you can recite "depreciation is added back on the cash flow statement" — every prep book says that. What they're testing is whether you understand why, well enough to handle a variant you haven't memorized: What if it's an increase in accounts receivable instead of depreciation? (Net income unaffected on the income statement, but cash flow from operations falls — you booked the sale as revenue, but haven't actually collected the cash yet, so accounts receivable, an asset, goes up while cash doesn't.) What about a stock buyback funded by new debt? (Cash out, treasury stock up on equity side — reducing equity — debt up on the liability side, cash swings through financing activities, not operations.)

The skill is tracing any transaction through all three statements from first principles — not having three memorized answers for three memorized questions.

The five words that make this teachable: "where did the cash go"

Every line item on the cash flow statement is answering one question: for this specific change, where did the actual cash go (or come from), and does that match what the income statement or balance sheet implied? If revenue went up but a receivable also went up by the same amount, the honest answer is: the cash hasn't arrived yet. If an expense was booked but no cash left the building (depreciation, stock-based compensation, deferred tax movements), the honest answer is: add it back, because the income statement charged you for something that isn't a real cash outflow this period.

How to actually practice this

This site's own Company Profile module pulls real 10-K figures for any US-listed company — real revenue, real depreciation, real changes in working capital, straight from SEC filings. Pick a real company, pull up two consecutive years of its balance sheet, and try to explain every single line item's change using only its income statement and cash flow statement for that year. If you can't explain a line, that's exactly the kind of gap this exercise is built to surface before an interviewer finds it for you.