Investing.com - The current bull market has drawn plenty of comparisons to those of the past.It's generally agreed that it the second longest since World War II, but after that comparisons become a bit fuzzy.Generally speaking, there have been nine, but there's some disagreement on the beginning and ending of each of them. The current bull market is, give or take, 108 months, or 9 years old. That definitely makes it the second longest since World War II. The duration of the longest one, however, is open to debate. It either ran from 1987 to 2000 or 1990 to 2000. So, at the most it lasted 12.8 years, which blows away the current one. At the least, it stretched nine and a half years, or 115 months, which puts the current one pretty close.Overall, the current bull market looks to be in the middle of the pack. Four in history lasted more than 12 years. The longest was slightly more than 15 years, stretching from the late 1940s to the early 1960s. Four bull markets lasted well less than 9 years. The shortest being 2.5 years in the early 1970s.Though much is made of bull markets, they are pretty much the status quo for stocks. Since the early 1970s, stocks have been in one bull market or another in all but four of those years.