Stock-market valuations, by one measure, have hit levels surpassed only a few times in the past, including the Great Depression and the dot-com bubble.
"It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of light, it was the season of darkness, it was the spring of hope, it was the winter of despair."