From an investment standpoint, market conditions remain characterized both by obscene valuations and still-negative market internals. It's that combination that continues to suggest potentially vertical downside risks.

When people think about crashes, they tend to think about an event – as if some massive, grotesque, red, scaly, fire-breathing, razor-toothed catalyst should be obvious beforehand. But we know from history that that's not the way it works.

Instead, the sequence goes like this: the conditions that create vulnerability to a crash emerge first (elevated valuations coupled with deterioration in market internals and/or widening in credit spreads), the crash emerges second, and catalysts are then identified – often just flashpoints that were consistent with speculative breakdown. Many investors think that "Lehman" caused the global financial crisis, but the mortgage crisis was already unfolding well before that. Lehman and Bear Stearns before it were only symptoms, not causes.