Lubin Investment · Blog

Price-to-earnings vs price-to-free-cash-flow: why one can mislead

2026-06-22 ·

The price-to-earnings ratio uses accounting earnings that companies can legally manipulate: depreciation schedules, R&D capitalization, revenue timing, stock-based compensation. The price-to-free-cash-flow ratio measures money that physically entered the bank. That is why our screener uses only this second ratio: no accounting trick can disguise it.

Why is the price-to-earnings ratio so popular?

The price-to-earnings ratio divides the share price by the net earnings per share. It is simple, universally available, and has been compared across decades. But that popularity hides a fundamental limit: earnings is an accounting construct. It is not money entering the bank. It is a figure calculated according to rules that companies can influence legally.

Four legal ways to shape accounting earnings

First: depreciation schedules. A machine bought for 100 million can be depreciated over five or ten years — a legal choice that changes annual earnings without changing operational reality. Second: R&D capitalization. The same expenditure, two different treatments. Third: revenue recognition timing. Fourth: stock-based compensation treatment.

Why the price-to-free-cash-flow ratio is more robust

Free cash flow is calculated as operating cash minus capital expenditures. Accounting earnings can be adjusted dozens of ways. Free cash flow can be adjusted far less: either the money arrived in the bank account or it did not.

Comparison: price-to-earnings vs price-to-free-cash-flow

CriterionPrice-to-earningsPrice-to-free-cash-flow
What it measuresNet accounting earningsReal cash after capex
Legally manipulable?Yes — depreciation, R&D, SBC, timingMuch less — cash is or is not there
Reflects capex?No — investments flow through deferred depreciationYes — capex is deducted directly
Misleading exampleNike: ratio looks normal, but FCF margin is 0.7%Nike: 196× reveals reality
Counter-intuitive exampleKinsale: 25× looks expensiveKinsale: 7× reveals true price paid
Use in our screenerNot usedExclusive central criterion

Real cases: three companies, two very different readings

CompanyApparent P/EReal price-to-FCFExplanation
Nike (NKE)~35×196×FCF margin of only 0.7%: capex and costs absorb almost all the cash
Kinsale Capital (KNSL)~25×~7×Exceptional FCF margin in specialty insurance
PayPal (PYPL)Appears high~8×Massive cash generation from a light-capex model

Nike: when brand hides the cash reality

Nike is the most striking example. Its price-to-earnings ratio sits in a seemingly accessible range. But the FCF margin comes in at 0.7%: logistics capex and inventory cycles absorb the rest. The price-to-free-cash-flow ratio reaches 196×.

Kinsale: when the price-to-earnings ratio overstates the cost

A price-to-earnings of 25× can look expensive for an insurance company. But Kinsale's specialty surplus lines model generates an exceptional FCF margin with structurally minimal capex. The price-to-free-cash-flow ratio comes in around 7×.

PayPal: when accounting earnings understate cash

PayPal's accounting earnings are weighed down by acquisition intangibles amortization and stock-based compensation. But the business model generates cash almost mechanically with very modest capex. Its price-to-free-cash-flow ratio comes in around 8×.

Why our screener uses only the price-to-free-cash-flow ratio

The Lubin method rests on a simple principle: measure what cannot easily be fabricated. Our screener uses price-to-free-cash-flow as its exclusive valuation criterion. Nike at 196× does not pass our threshold. Kinsale at 7× passes with room to spare.

FAQ

Is the price-to-earnings ratio truly useless?

No. It provides a quick order of magnitude. But it must always be cross-checked against the price-to-free-cash-flow ratio to verify that accounting earnings actually reflect a cash reality.

Can a company have a low price-to-free-cash-flow and a high price-to-earnings at the same time?

Yes, that is exactly the PayPal case. It happens when accounting earnings are reduced by large non-cash charges while operating cash flow remains high.

Why is capex so important in the free cash flow calculation?

Because capex represents money the company must spend to maintain its production base. A company generating 1 billion in operating cash but spending 900 million on capex has only 100 million in real free cash flow.

Does Nike really have a price-to-free-cash-flow of 196×?

Yes, at the time of this analysis. Its FCF margin comes in at 0.7%. Our screener gives it a score of 3 out of 10.

Can the price-to-free-cash-flow ratio also be manipulated?

To a lesser degree. A company can temporarily cut capex. But these moves are visible in the financial statements and hard to sustain durably.

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About the author

Written by Lubin Danilo, founder of Lubin Investment. A self-taught individual investor, I have analyzed stocks through their fundamentals for several years and invest my own money with this method. I codified it into a tool that judges a company's quality and its price separately, using criteria drawn from the financial literature (Warren Buffett, Michael Mauboussin, Aswath Damodaran).