this all major bull runs in the stock market since 1920:

1. *1920-1929*: 9-year bull run, ended with the Great Crash of 1929

2. *1932-1937*: 5-year bull run, ended with a recession

3. *1942-1946*: 4-year bull run, driven by WWII and post-war growth

4. *1949-1956*: 7-year bull run, marked by post-war economic expansion

5. *1958-1961*: 3-year bull run, ended with a recession

6. *1963-1968*: 5-year bull run, driven by economic growth and social change

7. *1970-1973*: 3-year bull run, ended with the 1973-74 bear market

8. *1975-1976*: 1-year bull run, short-lived due to high inflation

9. *1980-1987*: 7-year bull run, ended with the Black Monday crash

10. *1990-2000*: 10-year bull run, driven by the dot-com bubble

11. *2003-2007*: 4-year bull run, ended with the Global Financial Crisis

12. *2009-2020*: 11-year bull run, driven by monetary policy and economic recovery

Note: The duration and timing of bull runs can vary depending on the source and criteria used.

As for the current bull run, it started in March 2020 and is still ongoing, making it around 4 years long. However, please keep in mind that bull runs can end unexpectedly, and it's essential to stay informed and adapt to changing market conditions.