Why hasn't the market collapsed yet?

Question

First Layer: Implicit Expansion of the Balance Sheet and the “Inflation Trap”

1.1 From Quantitative Tightening to Implicit Easing Turning Point

Although official rhetoric still maintains a tone of “fighting inflation,” the Federal Reserve’s actual balance sheet operations have undergone a subtle yet critical shift. Economic data shows that after the tightening cycle in 2025, the Fed began injecting liquidity back into the system in early 2026 through so-called “reserve management purchases.” As of the first quarter of 2026, the Fed’s balance sheet remained at a high level of $6.64 trillion, halting the previous aggressive balance sheet reduction.

This operation is interpreted by the market as a return of the “Fed safety net.” The logic is: up to 47% of U.S. household wealth is invested in the stock market (excluding primary residences). According to data from the Investment Company Institute, U.S. retirement assets, including 401(k)s and IRAs, reached a record $48.1 trillion in Q3 2025. Under this structure, any sustained collapse in asset prices would quickly transmit through the “wealth effect” to consumption, destroying the economy. Therefore, a firm consensus has formed in the market: the Fed will not tolerate systemic collapse; once markets bleed, easing will follow.

1.2 Conditions for the Safety Net’s Dissolution: Persistent Core Inflation

The only nemesis of this safety net is inflation. Data from late 2025 to early 2026 indicates that inflation has not reverted linearly to the 2% target as expected. Latest figures show that core CPI, excluding food and energy, remains in the range of 2.6% to 3.0% year-over-year, with service sector inflation (especially excluding housing) still robust.

If energy prices surge due to geopolitical conflicts (such as escalation in the Middle East), the Fed will face a “stagflation” dilemma. In this scenario, rate cuts will ignite inflation, while maintaining high interest rates could lead to fiscal collapse. Once inflation remains above 3%, the Fed’s safety net will be thoroughly torn apart, and the market will lose the buyer willing to “pay any price” in times of crisis.

Second Layer: The Rigid “Buy Machine” with a Scale of 48 Trillion

2.1 The Irreversible Tide of Passive Investment

The second major buffer in the market is its extreme increase in passivity. By early 2026, passive investments (index funds and ETFs) accounted for over 55% of U.S. fund assets, up from just 19% in 2010. This means that for most American households, investment decisions are no longer based on judgments about individual stock P/E ratios or macroeconomic outlooks but are driven by fixed payroll deduction plans.

Data from the Investment Company Institute shows that about 62% (around $5.7 trillion) of assets held in 401(k) plans are allocated to mutual funds, most of which are invested in the S&P 500 index fund on a fixed cycle (e.g., biweekly). This “regardless of price levels, forced buying” mechanism forms the deepest bottom layer of market support.

2.2 Dissecting the S&P 500: Extreme Concentration and Position Risks

However, this massive buying machine is intensifying structural distortions in the market. The S&P 500 is a market-cap-weighted index, meaning that each dollar flowing into it is not evenly distributed among 500 companies but is heavily concentrated in the top firms.

By early 2026, data shows:

Concentration: The so-called “Magnificent Seven” (Microsoft, Apple, Nvidia, Google, Amazon, Meta, Tesla) account for about 30% to 33% of the S&P 500’s weight.

Industry Monopoly: The information technology sector’s weight has soared to 33.4%, surpassing the combined total of financials, healthcare, energy, and other sectors.

This means that the current “bull market” is essentially driven by the inflated market caps of a few tech giants.

2.3 Key to System Reversal: Aging and Rising Unemployment

This machine has two inherent destructive switches:

Employment Collapse: The momentum of the 401(k) system depends on continuous salary inflows. If unemployment rises significantly from the current 4.4% (e.g., above 6%), this positive inflow will stagnate and may turn into early withdrawals or defaults on 401(k) loans, turning “rigid buying” into “rigid selling.”

Intergenerational Transfer: The post-war baby boomers are the largest wealth holders in history. As they reach retirement age, they will shift from the “accumulation phase” (buying) to the “dissipation phase” (selling). This will fundamentally change the flow dynamics of the past 15 years, from a “faucet” (buying) to a “drain” (selling).

Third Layer: CTA and Algorithms—The Double-Edged Sword of Trend Followers

3.1 Dominance of Systematic Strategies

Intraday volatility and short-term trends are no longer primarily determined by fundamental analysts but are dominated by computer algorithms. The most representative are commodity trading advisors (CTAs), trend-following funds. These algorithms do not perform fundamental judgments; they do one thing: buy when prices rise, sell when prices fall.

Goldman Sachs data shows that demand from CTAs has become the largest marginal price setter in the market. During a recent market panic (due to tensions in Iran), CTAs issued strong buy signals. Data indicates that as of April 2026, CTA’s nominal US stock purchases over the past five trading days reached $86 billion, ranking among the top five in history. This massive buying force instantly overwhelmed market panic, forcing indices higher.

3.2 Forward Guidance from Models

More noteworthy is the predictive power of these models. Goldman Sachs’ futures strategy model indicates that even if the market remains flat over the next few days, CTA groups will still add about $70 billion in purchases over the next five trading days.

This “model demands buy regardless of future gains or losses” explains why markets continue to creep upward in the absence of major positive news. It is essentially a “volume-weighted average price” raiding, where computer programs passively absorb all sell orders using their capital advantage.

3.3 Critical Point of Algorithm Collapse

The risk of algorithms lies in their resonance effect. CTAs are designed to mechanically sell during declines to control drawdowns. Once US stocks fall beyond a certain threshold (e.g., 5-7% from the high), all algorithms will instantly switch from “maximum holdings” to “maximum short” or “panic selling.”

The March 2020 situation proved that markets driven by algorithms lack proactive “bottom-fishing”; only “stampedes.” At that time, programmed sell orders ignored valuations, dragging markets into deep declines until the Fed intervened. Therefore, while this mechanism currently supports the market, a sufficiently large external shock (catalyst) can turn it from the most solid buyer into the most ruthless seller.

Fourth Layer: Volatility Suppression and the “Gamma Trap”

4.1 Options Hedging as a Stabilizing Mechanism

The last line of defense comes from derivatives markets, mainly driven by options market makers. To maintain market neutrality, market makers who sell put options to speculators must hedge their delta positions in the underlying.

The operational logic is: when the market dips slightly, the value of their put options increases (delta rises), and to stay neutral, they must buy stocks during the decline. This “buy low” behavior physically slows down the decline. Conversely, when the market rises, they sell.

This mechanism acts as a damper on most trading days, smoothing volatility.

4.2 The “Paradigm” of Retail Culture and Bottom-Fishing

Additionally, the popular “bottom-fishing culture” among retail investors reinforces this effect. Over the past 15 years, every dip has been met with an even stronger rebound, creating a conditioned reflex that “market declines = buying opportunity,” which accounts for about 20% of daily trading volume.

4.3 Mechanism Failure: Reverse Gamma and the Collapse of Faith

However, this mechanism is not foolproof. When markets decline sharply and rapidly (gap down), the delta hedging model fails, and the system enters a “reverse gamma” state. In this state, market makers are forced not only to sell during declines but to continue adding sell orders at even lower prices to meet risk controls, accelerating the crash.

Moreover, the “bottom-fishing” belief is not eternal. During certain geopolitical shocks in 2025-2026 (such as early Iran incidents), markets did see some “bottom-fisher” hesitation. Once retail investors’ “diamond hands” belief collapses, the market loses its last liquidity providers, leaving only algorithmic sellers against short-sellers, with potentially disastrous consequences.

Potential Powder Keg: Debt, AI Bubble, and Pension Time Bomb

Although the four layers are still functioning, three major structural risks are significantly eroding these firewalls’ effectiveness.

5.1 Debt Spiral and Bond Market Uprising

$38.98 trillion in debt is an absolute number that cannot be repaid, but the real threat lies in interest payments. As of March 2026, the weighted average yield on tradable U.S. Treasuries has risen to 3.365%, far above the 1.499% five years earlier.

If long-term U.S. bond yields (10-year or 30-year) rise to 5% or even 6% due to inflation expectations or fiscal concerns, capital will undergo a “major asset switch” from equities. Investors will find that risk-free government bond yields have already exceeded the earnings yield of the S&P 500. At that point, even if the Fed cuts rates, capital outflows will not stop because the relative valuation relationship has been reset.

Recent bond auctions show that while demand for 2-year Treasuries remains decent (bid-to-cover ratio of 2.65), the market’s capacity to absorb long-term bonds remains fragile. If demand cools and yields spike, valuations in equities will be reset.

5.2 The “Disillusionment Valley” of AI

The current narrative supporting the high valuation of the “Magnificent Seven” is the AI revolution. However, according to the technology maturity curve, any disruptive technology (including the internet) tends to go through a “disillusionment valley” after overhyped expectations.

This critical point is approaching. AI’s capital expenditure (buying Nvidia chips) is enormous, but the cash returns from end applications have yet to fully materialize in enterprise software and consumer markets. If companies start reducing AI capital spending or earnings reports show AI has failed to convert into profits, the tech stocks that make up 33% of the index will face a double whammy of earnings and valuation collapse. Since the S&P 500 is market-cap weighted, a collapse in this sector alone could infect the entire market, which no amount of diversification can prevent.

5.3 The Endgame of Macro Leverage

Whether it is the Fed’s safety net, passive buying, or algorithms, their effective operation depends on the overall economy being in balance. Latest employment data shows that although the U.S. unemployment rate remains at a relatively low 4.4%, some states like California and Washington have unemployment rates exceeding 5.0%. This structural weakness is a precursor to recession.

Once the economy enters a genuine recession, the four mechanisms discussed above will all reverse:

Fed Put failure: High inflation prevents rate cuts.
Passive outflows: Rising unemployment causes 401(k) contributions to stop or be forced to redeem.
Algorithmic stampede: Trend-following strategies shift from “chasing gains” to “killing declines.”
Delta hedging collapse: Market makers are forced to add margin during sharp declines.

Conclusion: Asset Allocation Logic Under the Policy Framework

The current market is not without risks, but these risks are masked by financial engineering and liquidity illusions. In this extreme “top” zone, traditional “buy and hold” strategies are exposed to asymmetric risks.

Based on the dissection of the four mechanisms above, strategic adjustments for different scenarios should focus on two dimensions:

During the system-maintenance phase (defensive offense):

Although valuations are high, the probability of an immediate crash is relatively low due to passive funds and algorithms. Investors should accept the reality that “markets may continue irrational,” but must adjust their exposures. Specific rules, such as how to use Wall Street’s internal rulebook (covering momentum factors and capital flow analysis) for screening, are key to differentiating performance in this period. Focus on holding assets validated by massive capital inflows, rather than bottom-fishing weak assets.

During the system-collapse phase (left-side hedging and hard assets):

When inflation data remains persistently high, unemployment claims surge, or U.S. bond auctions turn “disastrous,” switch strategies immediately. In this phase, correlations tend to become 1, and all stocks decline together. Survival strategies include:

Hard assets: Precious metals and commodities. In a fiat currency dilution environment caused by debt expansion, physical assets provide ultimate insurance.
Long volatility: Directly buying put options is the most effective tool against a crash, despite the cost during normal times.
Cash is king: In initial chaos, liquidity is crucial, giving you the ability to re-enter at the panic bottom.

In summary, the current market is a delicately balanced tower supported by liquidity. It has not collapsed because the four mechanisms are still functioning as intended. But it’s important to recognize: maintaining equilibrium for 15 years does not guarantee the same for year 16. When the critical point arrives, you will not want to hold assets still relying on passive 401(k) buying at the top.