On Thursday's close, the current bull market will likely become the second longest in history.
If we define a bull market as a period of time in which the rises 20 percent from its prior low and does not subsequently fall 20 percent from a high it has hit, the current bull market dates to March 9, 2009, and has lasted 2,606 calendar days, through Wednesday's close.
That ties the second-longest bull market ever, which started on June 14, 1949, and ended on Aug. 2, 1956. Incidentally, this period entirely predates the actual creation of the S&P 500 index in 1957, but the S&P 90 was actively tracking stocks at that time, and the indexes have since been combined into a cohesive time series.
So long as the S&P 500 does not crash Thursday, this will officially become the second-longest bull market ever, as far as the calendar goes. If counting market sessions, one must wait a bit later, until mid-May. (All of these stats have been provided to CNBC by S&P Dow Jones Indices senior index analyst Howard Silverblatt.)
According to Chris Verrone, technical analyst at Strategas Research Partners, investors shouldn't be too concerned about the length of the technical bull market.
"It's probably not the most meaningful data point that this is seven or eight years in the tooth, simply because there's been some good shakeouts along the way," Verrone said Wednesday on CNBC's "Trading Nation," referring to some recent rocky periods for stocks.
In addition, the all-time length record is still a ways off. The bull market starting in October 1990 and ending dramatically in March 2000 lasted for 2,452 days — during which time the S&P 500 rose by 417 percent.