The nine-year bull market is at a historic threshold, but don't get carried away celebrating just yet.
The bull run turns 3,453 days old Wednesday after the close of trading. That makes it the longest market rally, besting the previous record from October 1990 to March 2000.
And that has given many investors reason to cheer since the S&P 500 index climbed more than 320 percent from its low of 666 in March 2009.
Despite those gains, the effects of the financial crisis still loom. Recent research from the Federal Reserve Bank of San Francisco estimates that the crisis cost every American about $70,000 in lost lifetime income.
Investors' memories, however, seem to have recovered. A Bank of America Merrill Lynch survey of fund managers found that they are the most bullish on U.S. stocks than they have been since 2015.
Still, a downturn — or even a correction — can come at any time.