Complexity researchers who study the behavior of stock markets may have identified a signal that precedes crashes.
They say the telltale sign is a measure of co-movement, or the likelihood of stocks to move in the same direction. When a market is healthy, co-movement is low. But in the months and years before a crash, co-movement seems to grow.
Regardless of whether stock prices go up or down or stay the same, they do so in tandem. People are copying each other, and a small nudge can send everyone in the same direction. The system appears primed for collapse.
“One of the most important things happening now is that economists are trying to understand, what is systemic risk? When is the entire system vulnerable to disaster? Our results show that we have a direct, unambiguous measure of that vulnerability,” said Yaneer Bar-Yam, president of the New England Complex Systems Institute.
Seen through an econophysicist’s eyes, a stock market panic is an avalanche.
Bar-Yam’s findings, released Feb. 13 on arXiv, are part of an emerging research field known as econophysics. It applies to economics insights from the physical world, especially from systems in which networks of interacting units produce radical collective behaviors.
Heated water turning to gas is one such behavior, known technically as a phase transition. Another is snow gathering into an avalanche. Seen through an econophysicist’s eyes, a stock market panic is an avalanche, too.
Keep reading here: Possible Early Warning Sign for Market Crashes | Wired Science | Wired.com.
