Valuation Ratios Part 1: PE, PS, and Price to Free Cash Flow

Valuation ratios separate investors who know what they own from speculators who are just guessing at numbers.

The price to earnings ratio is where most people start, and that makes sense because it answers the most intuitive question an investor can ask: how many dollars am I paying for each dollar of profit this company generates? The calculation looks dead simple. Take the stock price and divide it by earnings per share. If a stock trades at fifty dollars and the company earned two dollars per share last year, you have got a PE ratio of twenty five. You are paying twenty five times earnings.

But here is where it gets interesting and where most people stop thinking too early. That earnings number, what accountants call net income, lives at the very bottom of the income statement after every assumption, every depreciation schedule, every stock option expense, and every accounting choice management decided to make. Two companies in the same industry with identical cash coming in the door can report wildly different earnings based on how aggressive or conservative their accounting departments feel on any given quarter.

Let me give you something concrete. Back in the early two thousands, Amazon reported years of losses or minimal profits while reinvesting everything into infrastructure. The PE ratio was either nonexistent or absurdly high, sometimes over three hundred when they did show a profit. Traditional value investors looked at that and ran away. They were paying how much for earnings? Meanwhile, the company was building what would become the most dominant retail and cloud infrastructure on the planet. The PE ratio told you something, but it did not tell you what mattered.

Now flip that around. During the housing bubble, homebuilders like KB Home showed beautiful PE ratios, sometimes in the single digits. You could buy a dollar of their earnings for six or seven bucks. Looked like a steal. Except those earnings were fake in the sense that they depended on an unsustainable market that was about to collapse. The earnings existed on paper, the auditors signed off, but they evaporated the moment housing prices stopped climbing.

So PE ratios work best when three conditions hold. First, the company has stable, predictable earnings that reflect actual economic reality. Second, you are comparing companies in the same industry with similar accounting treatments. Third, you understand whether you are looking at trailing twelve month earnings or forward estimates, because those are two very different animals. Wall Street loves to quote forward PE ratios because they can make anything look cheap if you just believe hard enough in next year's projections.

Now let me talk about price to sales, which people turn to when earnings are problematic or nonexistent. This one divides market cap by total revenue. If a company has a market cap of ten billion dollars and generates five billion in sales, the price to sales ratio is two. You are paying two dollars for every dollar of sales the company brings in.

The appeal here is that revenue is much harder to manipulate than earnings. A company either sold something or it did not. Sales sit at the top of the income statement before management makes all those accounting choices about costs and expenses. For young companies that are growing fast but not yet profitable, PS ratios give you something to grab onto when PE ratios are useless.

But here is the problem. Revenue without profit is just busy work. I can start a company tomorrow that sells hundred dollar bills for ninety dollars each. My revenue will be fantastic. My price to sales ratio might look reasonable. And I will be bankrupt in three months. The PS ratio tells you nothing about whether the business model actually works, nothing about unit economics, nothing about whether growth is sustainable or just borrowed from future profits that will never arrive.

Think about WeWork before it imploded. The company had billions in revenue, real revenue from real leases. The price to sales ratio during the hype looked expensive but not insane for a high growth company. What the ratio did not show you was that every lease they signed lost money, that the entire model was structurally unprofitable, and that revenue growth was just digging the hole deeper. Sales matter, but profitability matters more, and PS ratios are blind to that.

The ratio works better in industries with consistent margins. If you know that software companies in a particular niche tend to have seventy percent gross margins and thirty percent net margins, then a price to sales ratio gives you a reasonable proxy for what the earnings multiple might look like once the company matures. But in industries with thin or variable margins, the ratio loses its power fast.

Then we get to price to free cash flow, which in my view is the most honest of the three but also the most misunderstood. Free cash flow is what is left after a company pays all its operating expenses and makes the capital expenditures needed to maintain and grow the business. This is real money that could be returned to shareholders or reinvested without damaging the core operations.

The calculation starts with cash from operations, which you find on the cash flow statement, then subtracts capital expenditures. If a company generates eight hundred million in operating cash flow and spends three hundred million on capex, free cash flow is five hundred million. Divide the market cap by that number and you have the price to free cash flow ratio.

Why does this matter more than earnings? Because cash is truth. Earnings can be gamed with accruals, with changes in reserve accounts, with timing of revenue recognition. Cash flow is harder to fake. When cash comes in the door, it shows up in the bank account. When it goes out, same thing. Free cash flow tells you what the business actually generates in spendable money.

Look at a company like Netflix during its growth phase. For years the earnings looked modest or negative because of content amortization and the accounting treatment of their massive spending on shows and films. But if you looked at free cash flow, you saw a different story. In some years it was deeply negative because they were spending more on content than they were bringing in. That told you something important. The business model required constant investment to feed the machine. It was not a bad business, but it was not a cash cow either, and the price to free cash flow ratio, when it even existed, made that clear.

On the other side, you get mature companies like Philip Morris or Coca Cola that generate enormous free cash flow relative to their market cap. These businesses require minimal reinvestment. The infrastructure is built. They just collect cash. A low price to free cash flow ratio on a company like that is genuinely attractive because that cash can be returned to you as dividends or buybacks.

The trap with this ratio is that free cash flow can be volatile. One year a company might have huge capex because they are building a new factory. The next year, nothing. If you just look at one year, you might think the business is in trouble or flush with cash when neither is true. You need to smooth it out over several years to see the real pattern.

And just like the others, this ratio is useless without context. A price to free cash flow of fifteen might be expensive for a utility and cheap for a biotech company. The number means nothing in isolation.

We are out of time. Next session continues with Part 2. When a ratio looks too good, ask what it is not showing you.