72

来源: 于 2023-10-08 19:02:18 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

if your annual return is X%, it will take Y years to double your money, where X * Y = 72

So, if your annual return is 6%, it takes 12 years to double and 24 years to quadruple  (4 times). 

So to quadruple in 20 years, your annual return has to be around 7.2%. 

That's SP500 index.