Listen to the deep-dive discussion – Cheap Money Hides Impurity (20:11 min)

 

“Only when the tide goes out do you discover who’s been swimming naked.”

— Warren Buffett

I. The Tide Goes Out

The 30-year U.S. Treasury yield has reached 5.19%—its highest level in nearly two decades. The last time yields were here was July 2007, on the eve of a financial crisis that redefined a generation of investors.

The proximate causes are familiar: inflation reignited by oil prices and the Iran conflict, sovereign debt concerns, a Federal Reserve caught between growth and price stability. The market commentary writes itself.

But there is a deeper story in this number. The 30-year yield is not just the price of long-term money. It is a revealer. When long-term money was free, it concealed the difference between businesses that compound naturally and businesses that must spend to grow. When long-term money has a price, that difference becomes visible.

The tide is going out. And the gradient is emerging from the water.

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II. The Era of Free Money

For most of the past fifteen years, capital cost almost nothing. The Federal Reserve held rates near zero from 2009 to 2015, raised them modestly, then slashed them again in 2020. For an entire generation of investors, the baseline assumption was that money was free.

This had a specific and underappreciated consequence: it compressed the gradient.

Every business has an A—the toll, the cash collected today—and a B—the wave, the structural growth that arrives over time. The cost of B varies enormously. For a Freesurfer like Visa, the B is free—every new electronic transaction arrives without capital expenditure. For a mechanical compounder like Microsoft’s Azure division, the B is expensive—growth requires data centers, infrastructure, engineers, and now $190 billion in annual capex.

When capital costs zero, the difference between a free B and an expensive B nearly disappears in the spreadsheet. A business spending $190 billion on growth financed at 0% carries almost no interest burden. The capex is real but the cost of capital is invisible. The Freesurfer and the mechanical compounder look almost identical in a discounted cash flow model when the discount rate approaches zero.

This is the great illusion of cheap money. It makes everything look pure. The gradient—from Natural B to Mechanical B, from growth inside the moat to growth outside the moat—was always there. But at zero rates, it was submerged. Every business looked like a compounder. Every management team looked like a capital allocation genius. The tide was in, and everyone appeared to be wearing a suit.

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III. The Gradient Decompresses

At 5.19% on the 30-year, the gradient re-emerges.

The arithmetic is simple and merciless. Microsoft’s $190 billion in annual capex, financed at 0%, carried no interest cost. At 5%, the same $190 billion carries roughly $9.5 billion in annual interest expense—a cost that did not exist three years ago. That is $9.5 billion subtracted from earnings, from free cash flow, from the capital available to return to shareholders. And the capex itself has not produced a moat—Azure is a level playing field, AI is a race. The $9.5 billion finances growth that is not protected.

Visa’s B costs nothing. At 0% or at 5%, the cost of Visa’s growth is zero. The number of electronic transactions worldwide increases regardless of the yield curve. Visa does not borrow to fund its growth. It does not issue equity. It does not divert cash from its franchise. The yield environment is irrelevant to the operating economics of the Freesurfer.

The spread between these two realities—$9.5 billion in financing costs versus zero—did not exist at zero rates. It was hidden. It is now visible. And it widens with every basis point.

This is what decompression looks like. The gradient was compressed by free money—the top and the bottom of the spectrum were squeezed together because the cost of capital was too low to differentiate them. As rates rise, the gradient stretches. The Freesurfer separates from the mechanical compounder. The quality of the B becomes measurable in dollars, not just in theory.

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IV. The Margin Revelation

There is a second force that cheap money concealed, more fundamental than the cost of financing.

Basic microeconomics teaches that on a level playing field—a market with no barriers to entry, no structural advantage, no moat—margins converge toward zero. Entrants see incumbents earning excess returns. They enter. They compete. Margins compress. In perfect competition, economic profit disappears.

This is not theory. It is the gravitational constant of capitalism.

But at zero rates, this gravitational force was suspended. When capital is free, even a business with thin margins and no moat can survive—and appear to thrive. It borrows at nothing, invests in growth, and reports revenue increases that look like compounding. The margins are thin, but the cost of capital is thinner. The business stays alive not because it has a franchise, but because money is free.

At 5%, the suspension ends. The gravitational constant reasserts itself.

A business with 5% operating margins and no moat, financing growth at 5%, has no economic profit. The cost of capital has consumed the margin. The excess return is zero—exactly what microeconomic theory predicts on a level playing field. The only thing that postponed this outcome was the illusion of free money.

A Freesurfer with 60% operating margins and a moat that no one can breach is untouched by this dynamic. Its margins are not under competitive pressure because there is no level playing field—the moat prevents entry. Rising rates do not compress its margins because the B costs nothing to finance. The gravitational pull of margin convergence does not reach inside the franchise.

The yield does not just reveal the cost of B. It reveals the fragility of unprotected margins. At zero rates, a business with weak margins and no moat looks like a compounder. At 5%, it looks like what it is: a commodity business running on borrowed time and borrowed money.

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V. Two Types of Naked Swimmers

When the tide goes out, two types of businesses are exposed.

The mechanical B outside the moat is doubly naked. Its stock price drops because higher rates increase the discount rate—the present value of future cash flows shrinks. And its business deteriorates because the cost of financing its growth has risen while its margins are unprotected. The price falls and the fundamentals weaken simultaneously. This is Microsoft’s Azure at $190 billion in capex on a level playing field. The stock drops and the economic return on the capex compresses.

The mechanical B inside the moat is partially exposed. Its stock price drops for the same duration reason—higher rates compress the present value of future earnings. But its business is protected. The moat prevents margin compression. A railroad’s operating margins are not under competitive threat because no one builds a second transcontinental network. GE Aerospace’s margins are captive for 30 years per installed engine. The price falls, but the fundamentals hold. Time resolves the gap. This is a Compression Harvest waiting to happen.

The Freesurfer appears exposed but is not. Its stock price drops because its duration is long—the value of decades of future free cash flows compresses when the discount rate rises. The market treats Visa like a growth stock in the discounted cash flow model. But the business is entirely insulated. The B is free. There is nothing to finance at 5%. The margins are protected by an infrastructural moat that no rate environment can breach. The price compresses while the business continues compounding at the same rate. The gap between price and value widens—and then closes as the market re-discovers what the framework always knew.

Buffett’s metaphor is precise. The tide reveals who is naked. But not everyone standing in the water is naked in the same way. Some are naked and drowning—the mechanical B outside the moat. Some are naked but swimming—the mechanical B inside the moat, temporarily compressed. And some are wearing a suit the tide cannot remove—the Freesurfer, whose economics are independent of the water level.

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VI. Hohn Saw the Tide

Chris Hohn’s Q1 2026 filing reads differently in the context of 5.19% yields.

He cut 84% of his Microsoft position. He increased Visa, S&P Global, and Moody’s. He opened a large new position in Alphabet. He kept GE Aerospace at 30% and maintained the railroads.

Read this through the lens of the tide going out.

Microsoft: mechanical B, outside the moat, $190 billion in capex now financed at 5%+, margins on Azure under competitive pressure from AWS and Google Cloud. The tide is exposing the naked swimmer. Hohn sold.

Visa, S&P Global, Moody’s: Natural B, inside the moat, zero cost of growth, margins protected by infrastructural and regulatory moats that no rate environment can breach. The tide is irrelevant to the suit they’re wearing. Hohn bought.

GE Aerospace, Canadian Pacific: Mechanical B, inside the moat, expensive but protected margins, captive return over decades. The tide lowers their stock price temporarily but cannot touch their economics. Hohn held.

Alphabet: Imperfect B, high-quality—75% natural, 25% mechanical, mechanical portion partially anchored, self-financed by the A. The tide compresses the price but the natural B dominates and the margins on Search are untouchable. Hohn bought at a compressed price.

Every position in Hohn’s portfolio is calibrated to the tide. The Freesurfers and monopolies survive it. The Imperfect B of high quality weathers it. The mechanical B outside the moat does not. Hohn didn’t just see the gradient. He saw the tide that reveals the gradient.

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VII. The Great Differentiator

Cheap money was the great equalizer. At zero rates, the gradient was compressed. The Freesurfer and the mechanical compounder appeared to live on the same planet. Every business looked like a quality compounder. PE multiples converged. Margin differences were masked by free financing. The market treated all growth as equivalent because the cost of producing that growth was invisible.

Expensive money is the great differentiator.

At 5%, the gradient decompresses. The cost of B becomes visible in dollars. Unprotected margins compress under the gravitational pull of competition. Mechanical B outside the moat becomes value-destructive—the financing cost exceeds the return. The Freesurfer separates from the field because its economics are structurally independent of the cost of capital.

The gradient was always there. The moat was always there. The cost of B was always different. The margins were always divergent. Cheap money did not eliminate these differences. It hid them.

Now the tide is going out. And the gradient is standing in plain sight.

The question for every investor is not whether rates will stay at 5% or return to 3% or climb to 6%. The question is whether the business you own is wearing a suit or swimming naked. Because the tide will go out again. It always does. And when it does, the only protection is the moat, the natural B, and the margins that no rate environment can reach.

The Freesurfer doesn’t wait for the tide. It stands above the waterline.

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Watch the Video

Related posts on averagingup.com:

The Imperfect B  ·  Hohn vs Ackman: Why $190 Billion Changes Everything  ·  The Purification Trade  ·  Inflation Doesn’t Punish Growth  ·  The Compression Harvest  ·  The Permanent Wave  ·  The Freesurfer

Based on the framework from The Infinite Investor, available at averagingup.com.