Now, imagine that you had made that same investment only 30 years earlier, in 1954. You probably imagine that you did even better. The economy was booming in the post-war/baby-booming 1950s and 1960s and was well into a new bull market by 1984. As it turns out, you barely broke even. Your $100,000 investment was worth about $120,000 a full 30 years later.
The chart below looks at the appreciation in the S&P over a rolling 30 year basis since 1900. The line at 1984 shows the appreciation of an investment made 30 years earlier, in 1954. The end of the line to the far right, at 2014, shows the appreciation if you had bought 30 years earlier, in 1984.