The cost of capital: money is never free

A company has £10 million sitting in its own bank account. A manager pitches a new warehouse that will earn a steady 7% a year on that money. “It’s our own cash,” she says. “It’s not costing us anything. A 7% return is free money.” The board nods. They are about to make a mistake — and to see why, you have to understand the one idea that governs every funding decision a company makes: money is never free. Not even your own.

The trap in “our own money”

The £10 million isn’t really the company’s to spend as it likes. It belongs to the people who put it there — the lenders who loaned it and the shareholders who own the company. Those people gave their money expecting a return. If the company can’t beat what they expect, it should hand the money back and let them earn that return elsewhere.

So “our own cash” is a fiction. Every pound a company holds was supplied by someone who wants it to work hard. The moment you spend it on a weak project, you’ve denied those suppliers the better return they could have had. That denied return is the cost. Economists call it opportunity cost — what you gave up by choosing this instead of the next-best thing. It is real even when no interest bill ever lands on a desk.

Debt has a price tag you can read

Earlier in this course you met debt and equity — the two ways a company raises money. Start with the easy one.

Debt costs interest. If a company borrows at 6%, that’s the price, in plain numbers, on a contract. Every year the lender takes their 6% before anyone else sees a penny. Miss it and they can force the company into court. The cost of debt is the loudest, clearest cost in finance — you can read it straight off the loan.

So far this matches the “free money” instinct, just adjusted: borrowed money costs 6%, our own money costs nothing. But that second half is where the mistake lives.

Equity costs more, not less

Here is the part that surprises almost everyone. The shareholders’ money — the equity — is the more expensive kind, not the free kind.

Think about where a shareholder stands. When profits are shared out, the lender is paid first, in full, by contract. The shareholder gets only what’s left — and in a bad year, what’s left is nothing. They stand at the back of the queue and carry the risk that there’s nothing when they reach the front. Nobody takes that deal for 6%. They take it because they expect more — more than the lender, precisely because they’re bearing more danger.

Put a number on it: if debt costs 6%, equity might cost 10%. The shareholders demand 10% a year, on average, or they’d rather buy the safer thing. That 10% is just as real a cost as the 6% interest — it simply never arrives as a bill. It shows up as the return shareholders quietly expect, and walk away when they don’t get.

So the instinct is backwards. The borrowed money is the cheap money. The “free” money — the company’s own equity — is the dearest of all.

Blending the two: the hurdle

Most companies use a mix of both. Say a company is funded half by debt, half by equity. What does its money cost overall? You blend the two costs, weighted by how much of each it uses:

cost of capital = (0.5 × 6%) + (0.5 × 10%) = 3% + 5% = 8%

That 8% is the company’s overall cost of capital — the weighted average of what every source charges. (Finance calls it the weighted average cost of capital, or WACC; the name just means “the blended price of all the money.”) The mix moves the number: all debt and it’s 6%, all equity and it’s 10%, half and half lands at 8%.

This 8% is the hurdle. It’s the bar every project must clear. The money the company would put into a project costs 8% a year to keep on hand. So a project has to earn more than 8% to be worth doing. Earn less, and you’d have been better off handing the money back to the people who supplied it.

Clearing it, or destroying value

Now return to the warehouse. It earns 7%. The cost of capital is 8%. The warehouse earns less than the money costs.

It still makes a “profit” in the everyday sense — 7% is a positive number, cash comes in. But it destroys value. The company tied up money that cost 8% in something that returns 7%, losing one point a year on every pound. Those pounds, returned to shareholders, would have earned them their 10% elsewhere. The warehouse looks like a gain and is quietly a loss.

Flip one number. A project that returns 9% clears the 8% hurdle by a point. That one creates value — it earns more than the money costs, so doing it leaves everyone better off than handing the cash back. Same company, same money, opposite verdict, decided entirely by whether the return beats the hurdle.

A company can lower its hurdle by leaning on cheaper debt — push the mix toward the 6% money and the blended cost falls. That’s real, and tempting. But debt brings its own danger; load up on it and a bad year can sink you. You’ll see how that trade works a couple of items from now.

Closing: your savings are the hurdle

The cost of capital is why a profitable-sounding plan can still be a bad use of money. “It earns 7%, it’s our own cash, it’s free” fails on both counts: the cash isn’t free, and 7% doesn’t clear the bar. Profit in the loose sense isn’t the test. Beating the cost of the money is.

And that bar isn’t set in a boardroom. It’s set by you. The return shareholders demand — the 10% in our example — is the return savers expect when they buy shares, directly or through a pension. Your expected return, multiplied across millions of savers, is the hurdle every company has to clear. When you decide what return makes a share worth holding, you set, in your small part, the height of the bar that decides which warehouses get built. The cost of capital sits between the saver and the project, and you are on both sides of it.