The most hostile subset of market conditions we identify couples overvalued, overbought, overbullish extremes with a breakdown in market action: deterioration of breadth, leadership and other market internals, along with a shift toward greater dispersion and weakening price cointegration across individual stocks, sectors and security types (what we sometimes call “trend uniformity”). The outcomes are particularly negative, on average, when that shift is joined by a widening of credit spreads. That’s a shift we observed in October 2000. It’s a shift we observed in July 2007. It’s a shift that we observe today.
My sense is that a great many speculators are simultaneously imagining some clear exit signal, or the ability to act on some “tight stop” now that the primary psychological driver of speculation – Federal Reserve expansion of quantitative easing – is coming to a close. Recall 1929, 1937, 1973, 1987, 2001, and 2008. History teaches that the market doesn’t offer executable opportunities for an entire speculative crowd to exit with paper profits intact. Hence what we call the Exit Rule for Bubbles: you only get out if you panic before everyone else does.