There is a chart on StockTwits that everyone is looking at.
It shows every major bull and bear market since 1920.
According to this chart, there have been 9 enormous bull markets. The largest bull market lasted 181 months and the market climbed 935.8%. That was in the 1940s and 1950s. The smallest bull market lasted 30 months in the late 1960s for a gain of roughly 75.6%.
Charts like this offer an incredible amount of perspective and insight into the market. Foremost, bull markets can last a long, long time. On the other hand, bear markets can be much shorter and much more devastating. Only two bear markets in history have lasted longer than 2 years: the Crash of 1929 and the Dot Com Bubble of 1999.
The chart is embedded below, and it was shared by Jerry Kerns and Morningstar. You may want to bookmark this for a later reference: