Expected Returns Ch. 2: The Risk-Free Rate Sets the Floor for Everything

Investment Background

Chapter 1 broke returns into a stack. This chapter handles the bottom layer.

The risk-free rate is usually treated as background noise — a number you see in the news that has nothing to do with your portfolio.

It is not background. It is what sets the price of every other layer.

The Wall Street Translation

Why It Is the Floor

The logic is simple and requires no model:

If Treasury bills pay 5%, then any risky asset must offer an expected return above 5%, or nobody would hold it.

So the risk-free rate is not merely one asset's yield. It is the hurdle every other asset must clear.

Which produces a direct and frequently overlooked corollary:

When the risk-free rate rises, every other asset must become cheaper to maintain its relative attractiveness.

Note what that means: share prices can fall with nothing whatsoever changing at any company.

It may be purely that the hurdle rose.

A Concrete Arithmetic

Watch the mechanism operate on a real valuation.

Imagine a perpetual cash flow paying $100 a year. What is it worth?

Its value is the cash flow divided by the discount rate.

Discount rate	Value of that cash flow
4%	$2,500
5%	$2,000
6%	about $1,667
8%	$1,250

Note: the cash flow never changed. It is still $100 a year.

And its value fell from $2,500 to $1,250 — cut in half.

The only thing that changed was the discount rate.

This is the mechanism behind what happened in 2022: as rates rose rapidly, stocks and bonds fell together. Many people found that confusing, because "diversification is supposed to help."

But if both are priced off the same discount rate, a change in that rate affects both.

This is one concrete mechanism behind the correlation convergence in Chapter 2 of When Genius Failed. That book establishes that correlations converge in a crisis; this chapter supplies one reason: many assets share a single pricing input.

Long-Dated Assets Are Hit Harder

This has a direct practical consequence worth stating separately.

The further away a cash flow, the more a change in the discount rate affects it.

Specifically: the present value of a cash flow arriving in thirty years is far more rate-sensitive than one arriving in three.

That is the essence of "duration," and it applies far beyond bonds:

Asset	Timing of cash flows	Sensitivity to rate changes
Treasury bills	Near	Low
Long Treasuries	Far	High
High-dividend mature companies	Nearer (paying now)	Medium
High-growth companies (profits in the future)	Very far	Very high

The last row explains a frequently misread phenomenon: why high-growth technology stocks fall more than value stocks during rate-hiking cycles.

The usual explanation is "sentiment turned." This chapter supplies a mechanical one: their cash flows are further away, so they are more sensitive to the discount rate.

No assumption about investor psychology is required.

Nominal and Real: A Distinction That Must Be Made

This chapter contains a trap, and it matters especially to retirees.

The rate you see in the news is nominal. Your living expenses are real.

The real rate is roughly the nominal rate minus expected inflation.

Why the distinction matters: a nominal 5% under 6% inflation means you are losing purchasing power.

Nominal rate	Inflation	Real rate	Your position
5%	2%	+3%	Purchasing power grows
5%	6%	−1%	Purchasing power shrinks
1%	3%	−2%	Purchasing power shrinks noticeably

The third row describes much of the 2010s. That was a period in which cash holders were systematically penalized.

This is the same mechanism as 1940–1981 in Chapter 2 of Stocks for the Long Run — where four decades of data show bondholders losing more than half their purchasing power.

What this chapter adds is the mechanical explanation: that was not bad luck. It was sustained negative real rates.

Executable Trading Rules

1. Always look at the real rate, not just the nominal one. The chapter's most practical line. Concretely: in the United States, the yield on Treasury Inflation-Protected Securities is the market's direct quote for the real rate. You need not estimate inflation expectations yourself; the market publishes them.

2. Understand your portfolio's overall duration, even if you hold no bonds. Ask: what fraction of my assets' value depends on cash flows in the distant future? A portfolio heavy in high-growth equities may be far more rate-sensitive than its owner realizes.

3. Do not misread a rate-driven decline as deteriorating fundamentals. This prevents a specific error. When rate hikes drive your portfolio down, those companies did not get worse. The discount rate changed. Understanding this helps you not sell into that decline.

4. When real rates are positive and meaningful, revisit your bond allocation. Not timing — Chapter 1's principle: use current yields rather than historical averages. A TIPS yielding 2% real is a certain real return you can simply read off a screen.

5. Do not try to forecast rates. A necessary qualification. Understanding how rates affect your assets and predicting where rates go are entirely different acts. The historical record on the second is poor — documented in A Random Walk and Chapter 2 of Where Are the Customers' Yachts?.

Relevance to a Retirement Portfolio

This chapter has two direct applications for retirees.

One, it explains why something like 2022 — stocks and bonds falling together — happens, and why it does not mean diversification failed.

Diversification protects you from company-specific, sector-specific, and country-specific risk. It cannot protect you from a change in a pricing input every asset shares.

That is not a flaw in diversification but its boundary. And the tool for that boundary is not more diversification — it is the cash buffer, because cash has near-zero duration and is barely affected when rates rise.

Two, it gives you a clean window onto current opportunity.

When real rates are positive, a retirement portfolio's position materially improves, for mechanical reasons:

• Your bond portion delivers real, predictable growth in purchasing power.
• Your cash buffer is no longer being silently eroded by inflation.
• The equity risk you must bear can fall accordingly.

When real rates are negative, the reverse: cash and bonds bleed slowly, which pushes retirees into more equity risk than they would otherwise choose.

Which is why "plan with current yields" is not pedantry. The same retirement plan requires completely different savings and withdrawal rates in a +2% real environment versus a −2% one.

Retirement Decumulation Mechanics gives you the withdrawal procedure; this chapter tells you where to read that procedure's input numbers from.

Chapter 3 handles the most tempting and most dangerous layer of the stack: premia that look like free return but are hidden risk.