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# Deep Cut 002｜AI崩壊で株も米国債も沈むのか——「逃げ場がない」論の欠けた条件｜AI Bust, Recession, Treasury Crash? The Missing Conditions Behind the “No Escape” Narrative
- URL: https://tokyobrainie.ghost.io/news-cutting-room-3f8bc361-d5151b0a-en/
- Published: 2026-11-11T03:00:00.000Z
- Updated: 2026-11-11T03:00:00.000Z
- Description: The verdict The Nikkei article is strongest when it argues that long-duration US Treasuries are no longer a guaranteed source of positive real returns. It is weakest
- Author: TokyoBrainie
- Tags: News Cutting Room, English, #Undated archive, #Import 2026-11-11 08:54

[English](https://tokyobrainie.ghost.io/news-cutting-room-3f8bc361-d5151b0a-en/) · [日本語](https://tokyobrainie.ghost.io/news-cutting-room-3f8bc361-d5151b0a-ja/)

アーカイブ移行日：2026年11月11日。原記事の初出日は未確認。 / Archived 11 Nov 2026; original publication date unconfirmed.

## The verdict

The Nikkei article is strongest when it argues that long-duration US Treasuries are no longer a guaranteed source of positive real returns. It is weakest when it turns that observation into a linear disaster story:

**AI boom fades → US recession → investors sell equities → fiscal stimulus expands → Treasury yields rise → stocks and bonds fall together → cash is the only refuge.**

Every arrow is possible. The chain as a whole is not automatic.

An AI bust is primarily a negative demand and investment shock. Unless it is accompanied by a new inflationary supply shock or a loss of fiscal credibility, it would normally weaken growth, reduce inflation pressure, lower the expected path of policy rates and create demand for liquid government securities. The Federal Reserve’s own severe-recession stress scenario makes exactly that distinction: equities fall, credit spreads widen, commodity prices decline and Treasury yields fall as inflation expectations recede.

The correct conclusion is therefore conditional:

> **A conventional demand-led recession tends to restore the hedge value of Treasuries. A stagflationary, fiscal-credibility or market-plumbing crisis can destroy it.**

## Four different meanings of “safe”

The article compresses several risks into the phrase “safe asset.” They must be separated.

| Safety dimension        | What it asks                                        | Long US Treasury                                            |
| ----------------------- | --------------------------------------------------- | ----------------------------------------------------------- |
| Credit safety           | Will principal be repaid in dollars at maturity?    | Very strong, though political and fiscal tail risks exist   |
| Liquidity safety        | Can it be sold in size?                             | Usually exceptional; can deteriorate during a dash for cash |
| Price safety            | Can it avoid mark-to-market losses before maturity? | Weak when duration is long and yields rise                  |
| Purchasing-power safety | Does it preserve real wealth after inflation?       | Weak when inflation exceeds the locked-in nominal yield     |

A 30-year bond bought near a historic yield low can lose heavily without the US missing a single payment. That is duration risk, not default. A decade-to-date loss for a long-duration Treasury index therefore does not prove that all Treasuries have stopped being safe. It proves that maturity matters.

Treasury bills, two-year notes and 30-year bonds are not one product. Treating them as one asset class hides the central decision: **which risk are you trying to hedge, and for how long?**

## Where the Nikkei argument is right

### 1\. The 2020s broke the easy 60/40 assumption

When inflation surprises became dominant after 2021, equity and bond returns turned positively correlated. Higher inflation raised expected policy rates and term premia while compressing equity valuations. Stocks and long-duration bonds could therefore fall together.

BIS research finds that inflation surprises became an important driver of the positive stock-bond correlation from mid-2021\. This weakened the diversification value of government bonds and encouraged investors to demand a higher term premium.

### 2\. Fiscal risk now matters more

Large and persistent deficits increase the supply of duration that private investors must absorb. IMF research finds that the relationship between projected debt and deficits, long rates and term premia has strengthened as the US fiscal position has deteriorated.

The Federal Reserve has also noted that far-forward rate premiums may reflect debt-sustainability risk. Publicly held debt is projected to rise markedly, and a recession can worsen the denominator and the deficit simultaneously.

### 3\. Treasury-market liquidity is not invulnerable

March 2020 showed that investors may sell even Treasuries to obtain cash. Leverage, margin calls, mutual-fund redemptions and limited dealer balance-sheet capacity can turn the world’s deepest bond market disorderly.

That is a serious structural risk. But it is a market-functioning problem, not proof that Treasury securities permanently lost their safe-haven role. Federal Reserve analysis found little evidence of a persistent retreat by foreign investors after the 2020 disruption; purchases resumed after the stress eased.

### 4\. The safe-haven signal has weakened at times

BIS research on the April 2025 shock found that the historical relationship between Treasury prices and measures such as the VIX weakened. Yet the same research found no evidence, at that stage, of a material sustained reallocation away from US assets. A weakening correlation is a warning, not a funeral certificate.

## Where the argument jumps the tracks

### Error 1: It confuses a bad historical entry price with permanent institutional decay

Long-duration Treasuries entered the 2020s with extremely low coupons and enormous duration sensitivity. Rising yields mechanically produced large mark-to-market losses.

That experience says:

- long bonds were expensive;
- inflation risk was underpriced;
- the starting yield was inadequate compensation;
- duration was mistaken for cash.

It does not say:

- Treasury bills cannot protect nominal capital;
- all maturities will fall in the next recession;
- the dollar reserve system has already failed;
- a Treasury default is the base case.

The correct lesson is “do not call duration cash,” not “US government debt is no longer a safe asset.”

### Error 2: It treats recession as if all recessions were inflationary

The source of the downturn determines the asset response.

A negative demand shock lowers spending, investment and pricing power. The expected policy-rate path usually falls. Government bonds tend to rally.

A negative supply shock lowers output while raising inflation. The central bank may be unable to ease. Stocks and nominal bonds can fall together.

An AI bust resembles the first mechanism more than the second: data-centre orders slow, capital spending is cut, semiconductor pricing weakens, wealth effects turn negative and credit creation contracts. It becomes stagflationary only if another force—energy scarcity, tariffs, deglobalisation, fiscal dominance or a currency shock—keeps inflation high.

The Fed’s own research describes Treasury duration as a hedge against adverse demand shocks because those shocks lead to lower interest rates in bad states of the world.

### Error 3: It assumes fiscal stimulus dominates monetary easing and safe-haven demand

A recession expands deficits through automatic stabilisers and discretionary policy. More issuance can raise the term premium.

But the same recession can also:

- reduce inflation expectations;
- bring forward Federal Reserve cuts;
- increase demand for liquid collateral;
- weaken private credit creation;
- lower the expected path of future short rates.

The ten-year yield is not a referendum on one story. It is approximately the expected path of short-term rates plus a term premium. Fiscal deterioration can push the second component upward while recession pushes the first downward. The net result is empirical, not predetermined.

### Error 4: “Everyone sells” is rhetoric, not a market mechanism

Investors cannot collectively convert the stock market into cash at yesterday’s price. Every sale requires a buyer; the price falls until a buyer accepts the risk.

The relevant questions are:

- who is leveraged and must sell regardless of price?
- who has cash or balance-sheet capacity to buy?
- do redemptions force funds to liquidate their most liquid holdings?
- do dealers have room to intermediate?
- does the Federal Reserve restore market functioning?

“Many investors sell at once” describes volatility. It does not identify the destination of aggregate wealth or prove that Treasury yields must rise.

### Error 5: A wealthy-client allocation chart does not prove a systemic run

A high equity weight among Bank of America wealth clients may reflect active buying. It may also partly reflect the rise in equity prices inflating the numerator. Without separating flows from valuation effects, the chart cannot establish that investors deliberately abandoned bonds on the scale implied.

It is also a selected population: affluent US clients are not global central banks, insurers, banks, pensions, money-market funds or foreign reserve managers. Allocation evidence is useful, but it is not the entire Treasury demand curve.

### Error 6: “Cash is king” is a horizon-specific trade, not a universal theorem

Cash and Treasury bills reduce duration risk and provide optionality. They are powerful during forced deleveraging.

But cash also carries:

- reinvestment risk when policy rates fall;
- inflation risk;
- currency risk for a yen-based investor;
- opportunity cost if long bonds rally;
- the risk of waiting permanently for a crash.

Gold is not “cash equivalent.” It has no fixed maturity value, can be volatile and can fall during liquidity squeezes. It can diversify monetary and geopolitical risk, but it solves a different problem.

## The scenario matrix the article should have shown

| Shock                                   | Growth            | Inflation | Fed path               | Long Treasuries                       | Equities     |
| --------------------------------------- | ----------------- | --------- | ---------------------- | ------------------------------------- | ------------ |
| AI capex bust / demand recession        | Down              | Down      | Easier                 | Usually up                            | Down         |
| Oil or supply shock                     | Down              | Up        | Constrained / tighter  | Down                                  | Down         |
| Fiscal credibility shock                | Down or uncertain | Up risk   | Ambiguous              | Down                                  | Down         |
| Deflationary financial crisis           | Sharply down      | Down      | Easier                 | Up, except temporary liquidity stress | Sharply down |
| Dash for cash / market plumbing failure | Down              | Mixed     | Emergency intervention | Can fall temporarily                  | Down         |
| Soft landing with heavy issuance        | Stable            | Sticky    | Higher for longer      | Vulnerable                            | Mixed        |

The “no escape” scenario occupies several rows, but not the first one. It requires more than an AI disappointment.

## When “stocks and Treasuries fall together” becomes the base case

TokyoBrainie would take the warning seriously if several of the following appeared together:

1. Long-run inflation expectations rise while growth expectations fall.
2. The ten-year term premium rises even as markets price Federal Reserve cuts.
3. Treasury auctions show repeated weak demand, large tails and falling indirect-bidder participation.
4. Swap spreads and cash-futures bases signal dealer balance-sheet stress.
5. Repo volatility and margin pressure force leveraged basis trades to unwind.
6. The dollar falls while long yields rise—a sign that foreign confidence, not merely growth, is being repriced.
7. Gold rises with inflation compensation, not merely with falling real yields.
8. Congress responds to recession with structurally unfunded spending rather than temporary stabilisation.
9. Energy, tariffs or supply-chain fragmentation keep services and goods inflation sticky during the downturn.

Without this cluster, “recession plus rising long yields” is a possibility, not the central forecast.

## Implications for Japan

For a yen-based investor, the hedge is two-dimensional.

**If the US enters a demand recession:**

- US equities and AI-linked earnings expectations weaken;
- Treasury yields are likely to fall;
- the dollar may weaken against the yen, reducing unhedged bond gains in yen terms;
- Japanese exporters and semiconductor equipment names face earnings and multiple pressure;
- banks may lose some benefit from global curve steepening;
- long-duration Treasuries can hedge equity risk, but FX can offset part of the return.

**If the US enters an inflationary or fiscal recession:**

- US equities and long Treasuries can fall together;
- the dollar response becomes crucial: safe-haven strength and fiscal-confidence weakness pull in opposite directions;
- Japanese long yields may face spillover pressure;
- growth stocks, REITs and leveraged companies are vulnerable;
- cash, short bills, inflation-linked instruments, gold and selected real assets become more useful—but none is a perfect refuge.

The practical lesson is not “buy no Treasuries.” It is to separate liquidity reserves from duration bets.

## A more defensible portfolio architecture

This is a research framework, not a universal allocation.

- **Operating liquidity:** yen cash and short-duration domestic instruments.
- **Dollar liquidity:** Treasury bills or short-duration US government exposure, with FX risk explicitly sized.
- **Recession hedge:** intermediate or long Treasuries only when inflation expectations are anchored and the shock is demand-led.
- **Inflation/fiscal hedge:** inflation-linked bonds, gold and selected real assets, recognising their own volatility.
- **Equity risk:** reduce concentration in AI beneficiaries whose valuation depends on uninterrupted capex growth.
- **Dry powder:** define a deployment rule; cash without a rule easily becomes permanent market timing.

Bill Gross’s “avoid bonds except one-year government paper” can be read as a duration view. It should not be misreported as proof that the entire Treasury market is uninvestable.

## Final verdict

The Nikkei article identifies a real regime change: inflation, fiscal supply and market structure have made long-duration government bonds less reliable as an automatic portfolio hedge.

But its final scenario commits a category error. It begins with an AI-led demand shock and ends with the asset behaviour of an inflationary fiscal or supply shock—without demonstrating the bridge.

> **The problem is not that the scenario is impossible. The problem is that the missing conditions are the whole story.**

A research-grade warning should say:

- If AI investment collapses and inflation falls, Treasuries can regain their hedge value.
- If AI investment collapses while inflation, fiscal risk or Treasury-market dysfunction intensifies, stocks and bonds can fall together.
- The portfolio response depends on the shock, maturity and currency—not on the slogan “cash is king.”

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[Original Notion archive](https://app.notion.com/p/3f8bc361ccd281729aa1ff53d5151b0a?pvs=204&ref=tokyobrainie.ghost.io)