Valuing Financial Firms, Part 4: Risk and the Discount Rate
We have the cash flows. Now we need to know what they’re worth. That depends on risk — and risk determines the discount rate.
In Parts 1 through 3, we built the numerator of a financial firm valuation. For a bank, that’s FCFE: the cash left after the bank funds its regulatory capital requirements. For an insurer, it’s normalized net income: what the business earns when you strip out catastrophes and reserve swings and look at the underlying engine.
Now we need the denominator.
In a discounted cash flow model, every future dollar of cash flow gets divided by a discount rate. The discount rate is what converts a future dollar into a present-day value. A dollar arriving ten years from now isn’t worth a dollar today — because money in hand today can be invested, and because the future holds uncertainty. The discount rate captures both of those realities.
Get the discount rate wrong, and the entire model is wrong. A rate that’s too low inflates every future cash flow and hands you a value that’s too optimistic. A rate that’s too high shrinks every cash flow and makes the business look cheaper than it really is.
This post explains how to arrive at the right discount rate for a financial firm.
Why WACC Doesn’t Work for Banks and Insurers
For non-financial companies — a retailer, a manufacturer, a software firm — we use a discount rate called WACC, which stands for Weighted Average Cost of Capital. WACC blends together two costs: the cost of debt (what the company pays to borrow) and the cost of equity (what shareholders require as a return), weighted by how much of each the company uses to fund itself.
The idea makes sense for an ordinary business: the company is funded partly by lenders and partly by shareholders, so the discount rate should reflect what both groups need.
For banks and insurers, WACC breaks down. We covered the core reason in Part 2: for a financial firm, debt isn’t financing — it’s raw material.
A bank takes in deposits, pays interest on them, and lends that money out at a higher rate. The spread between what it pays and what it earns is the business. Deposits aren’t layered on top of the bank’s operations; they are the operations. Treating them as “debt” in a WACC formula would be like counting a manufacturer’s steel inventory as a liability.
For an insurer, the equivalent raw material is the float — the pool of policyholder premiums held before claims are paid. The insurer earns a return on that float. It’s not financial leverage; it’s the working capital of the insurance business.
So when we value a financial firm, we skip WACC entirely. We go straight to the cost of equity — the return that shareholders require to own the stock. That’s the only discount rate that makes sense when all the obligations to lenders and policyholders are already embedded in the cash flow we’re discounting.
What Cost of Equity Means
The cost of equity is the return an investor demands in exchange for owning a share of the business.
Think of it from the investor’s perspective. You have money to put to work. You could put it in a US Treasury bond and earn a safe, predictable return. Or you could buy stock in a bank. If you’re going to take on the uncertainty of owning a business — the possibility that earnings disappoint, that the stock falls, that the company struggles — you want more than what the Treasury pays. You want extra return to compensate for the risk.
The cost of equity is the minimum return the investor requires to choose the stock over the safer alternative. If the business earns less than its cost of equity, shareholders are being shortchanged. They’d be better off elsewhere. If it earns more, it’s creating genuine value for its owners.
When we use cost of equity as the discount rate in a DCF, we are asking: given the risk level of this business, what return do shareholders require, and what are future cash flows worth in today’s dollars at that required return?
Estimating Cost of Equity: The CAPM
The standard method for estimating cost of equity is the Capital Asset Pricing Model, or CAPM. It sounds more complicated than it is.
CAPM says: the return an investor requires for owning a risky asset equals the return on a risk-free asset plus extra compensation for the risk taken. That extra compensation is measured by two things — how much extra return the stock market as a whole offers over Treasuries, and how much this particular stock moves relative to the market.
Three ingredients go into the formula.
Ingredient 1: The Risk-Free Rate
The risk-free rate is the return you earn on a US Treasury bond — the closest thing to a guaranteed return that exists in finance. US Treasuries are backed by the full faith and credit of the federal government. They’re the baseline: what you earn for taking no meaningful risk at all.
For most valuations, analysts use the yield on the 10-year Treasury note. It’s long enough to match the time horizon of a business valuation but short enough to be responsive to current market conditions. As of this writing, that rate is approximately 4.25%.
Ingredient 2: Beta
Beta measures how much a stock moves relative to the overall stock market.
If a stock has a beta of 1.0, it moves in lockstep with the market. When the S&P 500 rises 10%, the stock rises 10%. When the market falls 10%, the stock falls 10%.
If a stock has a beta above 1.0, it is more volatile than the market. A beta of 1.5 means the stock moves 1.5 times as much as the market — 15% when the market moves 10%.
If a stock has a beta below 1.0, it is less volatile. A beta of 0.7 means the stock moves 70% as much as the market — 7% when the market moves 10%.
Beta is a measure of market-related risk — the kind of risk that can’t be diversified away by holding many stocks. The higher the beta, the more risk the shareholder is taking, and the more return they require.
A Practical Note: We Use the Industry Beta, Not the Company’s Own
When you look up a company’s beta on a financial data site, you get a historical number — typically the slope of the company’s weekly or monthly returns against the market over the past two or five years. That sounds precise, but it has a serious flaw: a single company’s historical beta is noisy.
One large acquisition, a capital raise, a brief period of distress, a management change — any of these can bend a company’s stock behavior for a stretch of time and leave a beta estimate that reflects that event more than it reflects the underlying business risk. For a financial firm especially, which can see its stock move sharply during credit events or regulatory changes, the trailing beta is often a poor guide to the future.
The solution is to use the industry beta instead: the average beta across all companies in the same sector, as calculated by Professor Damodaran at NYU. Damodaran publishes these annually. By averaging across dozens of companies, the industry beta smooths out the idiosyncratic noise that distorts any individual company’s historical figure and gives you a better estimate of the risk level inherent to the business model itself — not the particular history of this one firm.
For banks, Damodaran’s industry beta runs roughly in the range of 0.7–1.0. For insurers, somewhat higher depending on line of business. We use those industry figures as our starting point, rather than pulling the raw historical beta from a data terminal.
Ingredient 3: The Equity Risk Premium
The equity risk premium — sometimes abbreviated ERP — is the extra return that investors demand for owning stocks instead of Treasury bonds.
Stocks are riskier than Treasuries. They can fall 30% in a bad year; they can lose decades of gains in a deep bear market. Investors accept that risk only if they expect to be rewarded for it over time. The equity risk premium is that reward — the average annual bonus, above the risk-free rate, that stocks must offer to attract investors.
Estimates of the ERP cluster around 4.5–5.0% for US equities in recent years. In our models, we use the implied ERP from Professor Aswath Damodaran at NYU, who calculates it monthly from current stock prices and earnings forecasts. That figure is currently approximately 4.72%.
The Formula
Put the three ingredients together:
Cost of Equity = Risk-Free Rate + Beta × Equity Risk Premium
This says: start with what you’d earn risk-free, then add compensation for the specific risk level of this investment — measured by how much the stock swings relative to the market (beta), scaled by how much extra return the market demands for that risk (ERP).
A Worked Example
Let’s use round numbers to make it concrete.
Suppose we’re valuing a regional bank with a beta of 0.9.
| Input | Value |
|——-|——-|
| Risk-Free Rate (10-yr Treasury) | 4.25% |
| Beta | 0.90 |
| Equity Risk Premium | 4.72% |
Cost of Equity = 4.25% + (0.90 × 4.72%)
= 4.25% + 4.25%
= 8.50%
The investors who own this bank require an 8.5% annual return. That is the discount rate we use to bring future FCFE back to today’s dollars.
Why Financial Firms Tend to Have Higher Betas
Earlier, in Part 2, First River Bank had a beta of 0.70. I noted that bank stocks tend to have betas below 1.0. Let me be more precise about the range — and why it varies.
Financial firms tend to have betas between 0.7 and 1.4, with substantial variation by type and business model. Here is why beta can run high for this sector.
Interest rate sensitivity. Banks earn their income from the spread between what they earn on loans and what they pay on deposits. When interest rates shift suddenly — when the Federal Reserve raises or cuts rates — that spread compresses or expands. Bank stocks are therefore sensitive to rate movements in a way that, say, a food company is not. A sudden rate hike can hit bank earnings quickly and meaningfully.
Credit cycle sensitivity. When the economy turns, loan losses rise. Mortgages go delinquent. Business loans default. A bank that looked healthy during the expansion can see its earnings hammered during a recession. This cyclicality is baked into the beta — bank stocks often fall harder than the market in downturns and recover sharply in upturns.
Catastrophe risk for insurers. A property and casualty insurer can see its earnings wiped out by a single hurricane season. When markets are pricing in economic distress — which often coincides with extreme weather or geopolitical events — insurance stocks can sell off sharply. That volatility raises the measured beta.
Leverage effects. Banks operate with significant leverage. A bank might have $1 of equity supporting $12 or $15 of assets. That leverage amplifies gains when things go well and amplifies losses when they go poorly. Higher leverage typically means higher beta, all else equal.
The practical implication: when estimating cost of equity for a large, stable commercial bank, a beta around 0.7–0.9 is reasonable. For a regional bank with more credit risk, 0.9–1.1. For a specialty insurer with meaningful catastrophe exposure, you might land at 1.1–1.3. The beta should reflect the actual risk profile of the business, not a generic assumption.
How Cost of Equity Plugs Into the DCF
In Part 2, we built a five-year DCF for First River Bank. Here is what that looked like at the key step:
Present Value of Year 1 FCFE = Year 1 FCFE ÷ (1 + Cost of Equity)¹
Present Value of Year 2 FCFE = Year 2 FCFE ÷ (1 + Cost of Equity)²
...and so on for each year.
The cost of equity appears in the denominator of every single calculation. It is the rate at which every future dollar of cash flow gets discounted back to today.
A higher cost of equity means a bigger denominator — which means a smaller present value for every future cash flow — which means a lower intrinsic value for the business.
This is not a technicality. It has real consequences.
Take First River Bank’s Year 1 FCFE of $212 million. At a cost of equity of 7.6%, the present value of that cash flow is about $197 million. At a cost of equity of 12%, the present value drops to $189 million. That’s a difference of $8 million on a single year. Multiply that difference across five years, then again across the terminal value, and the gap in total intrinsic value becomes significant.
The discount rate is the most powerful lever in a DCF model. Move it by 2 or 3 percentage points and the intrinsic value per share can shift by 20–30%. This is why getting the cost of equity right matters — and why it requires care and judgment rather than mechanical formula-plugging.
A Practical Note on Judgment
The CAPM formula gives you a precise number. That precision can be misleading.
Every input to the formula involves estimation. The risk-free rate changes daily. Beta estimates depend on the time period you use to measure them and can vary meaningfully from source to source. The equity risk premium is the subject of ongoing academic debate — estimates from different methodologies produce different answers.
The honest approach is to treat cost of equity as a range, not a point estimate.
For a US financial firm in the current environment, a reasonable range is roughly 9% to 13%. Here is how to think about where a specific company lands on that range:
Toward the lower end (9–10%): A large, well-diversified bank or insurer with a long track record of stable earnings. Low credit losses through cycles. Conservative underwriting. Investment-grade credit rating. Think of the major money-center banks or the best-capitalized national insurers. Their beta will tend to be lower, their earnings more predictable, their business model better understood.
In the middle (10–11%): A regional bank with solid fundamentals but more concentration in a specific geography or industry. Or a mid-size insurer with meaningful catastrophe exposure but strong reserving history. More uncertainty than the top tier, but not dramatically risky.
Toward the higher end (11–13%): A bank with elevated credit risk — heavier exposure to commercial real estate, a loan book concentrated in cyclical industries, or a history of reserve surprises. A specialty insurer with hard-to-model tail risk. A financial firm operating in a more volatile region or regulatory environment.
The formula gives you a starting point. The judgment is knowing whether the inputs reflect reality.
When in doubt, run the model at both ends of the range. If the business looks attractively priced at a 9% cost of equity and at a 12% cost of equity, you have a more confident conclusion. If it looks attractive at 9% but fully valued at 12%, the case depends heavily on which assumption you trust more — and you should be honest with yourself about that.
A Note to Luca and Lili
There’s a concept in physics called measurement uncertainty. The idea is that every measurement has some error built into it — not because the instrument is broken, but because the world doesn’t cooperate perfectly with our tools. You can be very precise and still be somewhat wrong.
Finance is the same way.
The CAPM formula looks like it produces an exact answer. You put in a risk-free rate of 4.25%, a beta of 0.90, and an equity risk premium of 4.72%, and out comes 8.50%. That feels precise. But every one of those inputs is itself an estimate, and the formula’s output is only as reliable as its ingredients.
This is not a reason to throw up your hands and refuse to do the calculation. The calculation is necessary — it disciplines your thinking and forces you to name your assumptions. But it is a reason to hold the result with appropriate humility. The output is a useful approximation, not a revealed truth.
One of the most important habits in analysis is being able to say: “My best estimate is 10%, but reasonable people could argue 9% or 11.5%, and the conclusion still holds across that range.” That kind of statement reflects more honesty — and more sophistication — than a model that pretends to know the answer to the decimal point.
I’d rather you be approximately right and know it, than precisely wrong and confident.
— Papa
The One-Sentence Summary
For a financial firm, cost of equity — estimated using the CAPM formula as the risk-free rate plus beta times the equity risk premium — is the discount rate that converts every future dollar of FCFE into today’s money, and getting it into the right range (roughly 9–13% for US financial firms) matters as much as getting the cash flows right.
Next: Financial Firms, Part 5 — Putting It All Together. We have the cash flows and the discount rate. Part 5 builds a complete valuation for a financial firm from start to finish.
— Jim