Skip to main content
No. of Recommendations: 0
intercst wrote If you look at the 128 rolling 30-year periods between 1871 and 2000 for an investment in the S&P500, more than 80% of those 30-year periods had an annualized, inflation-adjusted return of more than 5%.

I am not going to dispute the data - data for the early years must be very different. The idea one can expect to obtain 5% over inflation with the S&P is problematic based on S&P closings and inflation data.

From I found the S&P500 in January 1950 to be 17.05. Adjusted for splits the value in December 2010 in 1250. Call it 60 years.

1250/17.05 = 73.78 which for 60 periods is 7.42% compound growth.

I cannot prove this site is accurate (, but plugging in $20 for 1950 gets $181.58 today. Call it 60 years.

$181.58/$20.00 = 9.079 which for 60 periods is 3.74% annual growth.

So using the whole 1950 to 2010 period 7.42% - 3.74% = 3.50% or well below 5%.

I would not be surprised if several 30 year periods between 1950 and 2010 had 5% real returns, but it is impossible for 80% to have such returns without periods of dramatic disinflation - and that has not happened.

Print the post  


The Retirement Investing Board
This is the board for all discussions related to Investing for and during retirement. To keep the board relevant and Foolish to everyone, please avoid making any posts pertaining to political partisanship. Fool on and Retire on!
What was Your Dumbest Investment?
Share it with us -- and learn from others' stories of flubs.
When Life Gives You Lemons
We all have had hardships and made poor decisions. The important thing is how we respond and grow. Read the story of a Fool who started from nothing, and looks to gain everything.
Contact Us
Contact Customer Service and other Fool departments here.
Work for Fools?
Winner of the Washingtonian great places to work, and Glassdoor #1 Company to Work For 2015! Have access to all of TMF's online and email products for FREE, and be paid for your contributions to TMF! Click the link and start your Fool career.