In case the Bitcoin and FAANG stock manias have you envious and pondering a decision to abandon a thoughtfully crafted investment plan, we offer you the following wet blanket. This is now the most expensive stock market on record. The S&P 500 price-to-sales ratio shows that stocks have pushed through the highs, relative to sales, reached at the peak of the biggest stock market bubble in history.

High valuations aren’t usually a catalyst for a bear market, but starting valuations are still the single best indicator of long-term returns—with added emphasis on the long-term.