Recent crises have seen very large spikes in asset price risk without dramatic shifts in fundamentals. We propose an explanation for these risk panics based on self-fulfilling shifts in risk made possible by a negative link between the current asset price and risk about the future asset price....

There has been a long debate about whether speculators are stabilizing or not. We consider a model where speculators have a stabilizing role in normal times, but may also provoke large risk panics. The very feature that makes arbitrageurs liquidity providers in normal times, namely their...