Flight To Liquidity

In normal times, investors mostly care about risk and expected return, and liquidity is a secondary consideration — a somewhat less liquid bond that pays a bit more yield is a perfectly reasonable holding if you don't expect to need to sell it soon. In a crisis, that calculus flips. When nobody knows what's coming next, the ability to exit a position quickly and cheaply becomes valuable in its own right, independent of the asset's fundamental risk. Investors rush out of anything that might be hard to sell and into the handful of instruments everyone agrees can always be sold — a pattern called flight to liquidity.

Why liquidity itself becomes the priority

During stress, uncertainty about future needs rises sharply: an investor might suddenly need to raise cash to meet redemptions, margin calls, or simply to de-risk before things get worse, and they don't know in advance how much or how fast. Holding an illiquid asset in that environment is dangerous not because the asset is necessarily going to lose value, but because if you're forced to sell it under pressure, you might not be able to sell it at all, or only at a steep discount. The rational response is to prefer assets you know you can convert to cash quickly regardless of what happens next — even if that means accepting a lower expected return. This is why flight to liquidity often happens alongside, but is conceptually distinct from, "flight to quality" (fleeing to safer credit): a bond can be very safe from default risk and still get sold off in a liquidity flight if it's simply hard to trade in size quickly.

Worked example

Two US Treasury bonds have nearly identical maturity and credit risk (both are backed by the same government), but one is the most recently issued "on-the-run" bond, trading in huge volume with the tightest possible spreads, while the other is an "off-the-run" bond of similar maturity issued a year or two earlier, trading much less frequently. In calm markets, the yield difference between them might be just a few basis points, reflecting a small liquidity premium. During an acute stress episode, investors dump the harder-to-trade off-the-run bond in favor of the on-the-run one purely for its superior liquidity, and the yield spread between them can widen to 20-30 basis points or more — a substantial premium for an asset that carries essentially the same default risk, purely because one is easier to exit than the other.

What this means in practice

Flight-to-liquidity episodes tend to produce counterintuitive price patterns that break normal relative-value relationships: assets that "should" trade at similar prices based on fundamentals diverge sharply, purely on liquidity grounds, which is exactly the setup that can blow up relative-value and arbitrage strategies betting on convergence (as happened to several funds during past stress episodes that were short the liquid instrument and long the illiquid one). Recognizing flight-to-liquidity as a distinct force — separate from credit risk repricing — matters for risk management, because a widening spread during stress doesn't necessarily mean the market has revised its view of default risk; it may simply mean liquidity itself has been repriced.