Stop calling every market selloff a panic

Before calling a market selloff irrational, ask whether the sellers had a choice. An investor may sell because a lender requires more collateral. A fund may need cash to meet withdrawals. A portfolio manager may be responding to a risk limit that permits less exposure after volatility rises. None of those explanations requires a sudden failure to understand the asset.

"Panic" can describe a feeling without explaining a transaction. When the label becomes the explanation, it can obscure the constraint that made selling necessary. That matters because a market problem caused by fragile financing requires a different response from one caused by a mistaken belief.

Markus Brunnermeier and Lasse Heje Pedersen's 2009 paper linked market liquidity, the ease of trading an asset, with funding liquidity, the ease of obtaining financing. Their model showed how, under certain conditions, difficulties in funding and trading can reinforce each other. A deterioration in one can worsen the other and produce a liquidity spiral. The paper provides a mechanism to investigate, rather than evidence that every selloff follows that mechanism. Market liquidity and funding liquidity ↗

Consider a hypothetical fund that believes an asset remains attractive but must raise cash by the afternoon. Waiting for a better price may be unavailable. If other funds face similar requirements, they may sell at the same time without copying one another's investment judgments. Their transactions can look like herding even when a shared financing constraint explains the pattern.

The distinction becomes important for behavioral finance. Similar actions can arise from imitation, common information, or common constraints. A price chart does not reveal which one produced the movement. To argue that psychological pressure changed judgment, researchers need evidence about judgment and pressure, along with attention to the alternatives.

Stress may still contribute. A financing problem can make the environment more demanding, and demanding conditions may affect subsequent decisions. But a plausible interaction is not a measured effect. We should not look at a falling market, infer fear from the decline, and then use the inferred fear to explain why the market fell. That reasoning never encounters evidence capable of disproving it.

A serious account of a selloff should examine what changed in the available information, who needed cash, and which mandates or financing arrangements restricted their choices. Where the relevant data are unavailable, the explanation should retain that uncertainty. An incomplete account that identifies missing evidence is more useful than a vivid account that fills the gap with emotion.

For institutions, this suggests a more demanding simulation of market stress. It is useful to examine how positions respond to price changes. The organization should also consider whether financing remains available, how quickly it would need cash, and who has authority to act when normal approvals take too long. It can then investigate how people behave within those conditions.

Giving a team unlimited time and assuming that every position can be sold at a convenient price would omit much of the situation it claims to test. At the same time, creating artificial urgency without a plausible business reason may reveal little about actual operations. A useful exercise makes the constraints explicit enough for participants to respond to them and reviewers to assess the response.

Markets can misprice assets. Investors can misinterpret information, imitate others, and defend beliefs after the evidence changes. The case for studying those behaviors becomes stronger when the analysis distinguishes them from transactions that an investor could not reasonably avoid.

Financial commentary should make that distinction before recommending a cure. Teaching a forced seller to be less emotional will not provide the cash required by the deadline. A rule that overlooks financing can preserve a comforting account of rational behavior while leaving the source of instability intact.

When the next selloff arrives, follow the cash requirements as carefully as the prices. The evidence may support a behavioral explanation. It may also show that the people described as panicking were responding to contracts written long before the market turned.