Why Does Market Liquidity Always Disappear at the Worst Moment?

Analysis: A Resource That Vanishes at the Critical Moment

Imagine you own shares in a large company. Everything is fine, markets are calm, you could sell them in one click. Then a crisis hits. You look at your screen and realize something disturbing: there are almost no buyers. The price collapses, or worse, trading stops completely. That's a liquidity crisis.

Liquidity is a market's ability to absorb large transactions without moving prices excessively. A liquid market is one where you can buy or sell quickly, at the displayed price, without suffering a massive slippage between your order and execution.

In normal times, this liquidity seems infinite. Market makers — banks and high-frequency trading firms — stand on each side of the order book, ready to buy at one price and sell slightly above. They earn on the spread. This system works very well... until the risk becomes too great for them.

Historical Fact: March 2020, the Treasury Market Seizes Up

We often think that US government bonds (Treasuries) are the most liquid assets in the world. And that's true — in normal times. With $23 trillion in public debt and daily volumes of several hundred billion dollars, the Treasury market is supposed to be indestructible.

But in March 2020, during the initial COVID-19 shock, something unthinkable happened: even the Treasury market nearly froze. Within days, spreads on US government bonds widened to levels not seen since the 2008 crisis. Foreign pension funds and asset managers were selling Treasuries en masse to get dollars — not because they doubted US creditworthiness, but because they desperately needed cash to cover margin calls elsewhere.

The Fed had to intervene on March 23, 2020, announcing unlimited bond purchases and emergency liquidity facilities. Within 48 hours, markets stabilized. Without this intervention, the world was approaching a total freeze of the global financial system — far worse than what the general public witnessed.

The Anecdote: LTCM, or How Geniuses Forgot About Liquidity

In 1998, Long-Term Capital Management (LTCM) was run by two Nobel Prize economists (Myron Scholes and Robert Merton) and dozens of mathematics PhDs. Their models were sophisticated, their bets theoretically sound. The problem? These models assumed they could always unwind their positions in liquid markets.

LTCM had built colossal leverage: for every $1 of equity, they controlled roughly $25 to $30 in assets. Relying on arbitrage strategies that worked in normal markets, they had generated exceptional returns for 4 years.

Then Russia defaulted on its debt in August 1998. Markets panicked. And there, LTCM's perfect mathematical models met the real world: no one wanted to buy what they needed to sell. Their positions were so enormous that trying to liquidate them would have collapsed prices themselves, worsening their losses with every sale.

The New York Fed had to organize an emergency bailout with 14 major banks to avoid a systemic domino effect. LTCM lost $4.6 billion in less than 4 months. Geniuses, destroyed not by their mathematics, but by forgetting one simple rule: a model that ignores liquidity is an incomplete model.

"In the short run, the market is a voting machine. In the long run, it is a weighing machine." — Benjamin Graham

The Concept: The Liquidity Paradox and Correlation Risk

Here's what makes liquidity so dangerous to understand: it's abundant precisely when you don't need it, and scarce when you need it most. This is called the liquidity paradox.

In calm bull markets, everyone wants to buy, spreads are tight, order books are deep. Liquidity seems guaranteed. But as soon as a crisis hits, two things happen simultaneously:

1. Demand for liquidity explodes. Everyone wants to sell at once — funds facing massive client redemptions, traders receiving margin calls, institutions trying to reduce risk.

2. Supply of liquidity collapses. Market makers, seeing their own risk explode, widen their spreads or withdraw entirely. Natural buyers disappear because they're also afraid.

This double movement creates what economists call a "liquidity spiral": falling prices force forced sales, which push prices down further, which force more sales. It's self-reinforcing.

Another critical phenomenon: correlation between assets rises to 1 in a crisis. In normal times, your different assets are uncorrelated — when stocks fall, bonds rise, gold protects. But during a liquidity crisis, all assets fall together because everyone is selling everything to get cash. Diversification protects against normal risks, but not against systemic liquidity crises.

The Axone Lesson: Liquidity is not a permanent property of markets — it's a resource that dries up exactly when you need it most. Two practical reflexes to internalize: 1) Never take for granted that you can exit a position quickly and without cost. 2) In your portfolio, maintain a liquidity buffer (cash or equivalents) not to "miss opportunities," but to never be forced to sell at the worst moment. The discipline that prevents panic selling isn't just a psychological matter — it's also a portfolio structure question. This is at the heart of the Axone method: understand the system, not just the chart.