If you invested $100 in the S&P 500 at the beginning of 1987, you would have about $619.51 at the end of 2001, assuming you reinvested all dividends. This is a return on investment of 519.51%, or 12.93% per year.
This lump-sum investment beats inflation during this period for an inflation-adjusted return of about 297.38% cumulatively, or 9.63% per year.
If you used dollar-cost averaging (monthly) instead of a lump-sum investment, you'd have $577.40.
The graph below shows the performance of $100 over time if invested in an S&P 500 index fund. The returns assume that all dividends are automatically reinvested.
The nominal return on investment of $100 is $519.51, or 519.51%. This means by 2001 you would have $619.51 in your pocket.
However, it's important to take into account the effect of inflation when considering an investment and especially a long-term investment. You can convert S&P returns to their real (inflation-adjusted) value using an inflation calculation based on the U.S. Bureau of Labor Statistics Consumer Price Index (CPI).
In the case of the returns described above, the CPI in 1987 was 113.600 and the CPI in 2001 was 177.100.
The ratio between these CPIs describes how relative buying power of a dollar has changed over 14 years.
Adjusted for inflation, the $619.51 nominal end value of the original $100 investment would have a real return of roughly $297.38 in 1987 dollars. This means the inflation-adjusted return is 297.38% as opposed to the original 519.51%.
The table below shows the full dataset pertaining to a $100 investment, including gains and losses over the 180-month period between 1987 and 2001.
Note that data shown is the monthly average closing price. Returns include dividends.
Year
Month
Return (%)
Amount ($)
CPI
1987
1
6.46%
106.46
111.20
1987
2
4.38%
111.12
111.60
1987
3
-0.86%
110.17
112.10
1987
4
0.17%
110.36
112.70
1987
5
4.50%
115.32
113.10
1987
6
3.12%
118.92
113.50
1987
7
6.45%
126.60
113.80
1987
8
-3.03%
122.76
114.40
1987
9
-11.85%
108.21
115.00
1987
10
-12.30%
94.90
115.30
1987
11
-1.33%
93.63
115.40
1987
12
4.25%
97.61
115.40
1988
1
3.33%
100.86
115.70
1988
2
3.23%
104.12
116.00
1988
3
-0.89%
103.19
116.50
1988
4
-2.19%
100.94
117.10
1988
5
6.00%
106.99
117.50
1988
6
-0.31%
106.66
118.00
1988
7
-1.72%
104.83
118.50
1988
8
1.93%
106.85
119.00
1988
9
3.80%
110.91
119.80
1988
10
-2.02%
108.67
120.20
1988
11
2.33%
111.20
120.30
1988
12
3.51%
115.10
120.50
1989
1
3.30%
118.90
121.10
1989
2
-0.16%
118.71
121.60
1989
3
3.56%
122.94
122.30
1989
4
4.12%
128.00
123.10
1989
5
3.39%
132.34
123.80
1989
6
2.80%
136.05
124.10
1989
7
4.69%
142.43
124.40
1989
8
0.46%
143.08
124.60
1989
9
0.29%
143.49
125.00
1989
10
-1.81%
140.89
125.60
1989
11
2.74%
144.74
125.90
1989
12
-2.21%
141.54
126.10
1990
1
-2.53%
137.96
127.40
1990
2
2.71%
141.70
128.00
1990
3
0.20%
141.98
128.70
1990
4
3.85%
147.44
128.90
1990
5
3.17%
152.12
129.20
1990
6
0.17%
152.38
129.90
1990
7
-7.86%
140.40
130.40
1990
8
-4.34%
134.30
131.60
1990
9
-2.32%
131.19
132.70
1990
10
2.98%
135.11
133.50
1990
11
4.59%
141.30
133.80
1990
12
-0.69%
140.34
133.80
1991
1
11.61%
156.63
134.60
1991
2
3.04%
161.39
134.80
1991
3
2.26%
165.04
135.00
1991
4
-0.18%
164.74
135.20
1991
5
0.35%
165.32
135.60
1991
6
0.78%
166.61
136.00
1991
7
2.68%
171.07
136.20
1991
8
-0.30%
170.55
136.60
1991
9
0.18%
170.86
137.20
1991
10
0.02%
170.89
137.40
1991
11
0.94%
172.49
137.80
1991
12
7.36%
185.18
137.90
1992
1
-0.60%
184.06
138.10
1992
2
-1.01%
182.20
138.60
1992
3
0.26%
182.68
139.30
1992
4
2.07%
186.46
139.50
1992
5
-1.33%
183.98
139.70
1992
6
1.91%
187.50
140.20
1992
7
0.94%
189.27
140.50
1992
8
0.38%
189.98
140.90
1992
9
-1.18%
187.74
141.30
1992
10
2.76%
192.91
141.80
1992
11
3.27%
199.22
142.00
1992
12
0.14%
199.51
141.90
1993
1
1.72%
202.95
142.60
1993
2
2.15%
207.31
143.10
1993
3
-1.34%
204.53
143.60
1993
4
0.72%
206.01
144.00
1993
5
0.87%
207.79
144.20
1993
6
0.06%
207.92
144.40
1993
7
1.76%
211.59
144.40
1993
8
1.35%
214.45
144.80
1993
9
1.24%
217.12
145.10
1993
10
0.01%
217.13
145.70
1993
11
0.89%
219.06
145.80
1993
12
1.74%
222.86
145.80
1994
1
-0.08%
222.69
146.20
1994
2
-1.42%
219.52
146.70
1994
3
-3.35%
212.18
147.20
1994
4
1.06%
214.42
147.40
1994
5
1.11%
216.80
147.50
1994
6
-0.52%
215.67
148.00
1994
7
3.08%
222.32
148.40
1994
8
0.82%
224.14
149.00
1994
9
-0.44%
223.14
149.40
1994
10
-0.37%
222.32
149.50
1994
11
-1.03%
220.04
149.70
1994
12
2.45%
225.43
149.70
1995
1
3.82%
234.04
150.30
1995
2
2.56%
240.03
150.90
1995
3
3.22%
247.74
151.40
1995
4
3.35%
256.04
151.90
1995
5
3.18%
264.18
152.20
1995
6
3.55%
273.55
152.50
1995
7
0.51%
274.95
152.50
1995
8
3.72%
285.17
152.90
1995
9
0.91%
287.78
153.20
1995
10
2.36%
294.56
153.70
1995
11
3.39%
304.55
153.60
1995
12
0.16%
305.04
153.50
1996
1
5.90%
323.05
154.40
1996
2
-0.20%
322.40
154.90
1996
3
0.20%
323.04
155.70
1996
4
2.35%
330.65
156.30
1996
5
1.28%
334.87
156.60
1996
6
-3.48%
323.23
156.70
1996
7
3.08%
333.17
157.00
1996
8
2.02%
339.92
157.30
1996
9
4.12%
353.92
157.80
1996
10
5.05%
371.80
158.30
1996
11
1.20%
376.25
158.60
1996
12
3.26%
388.51
158.60
1997
1
4.36%
405.45
159.10
1997
2
-0.62%
402.92
159.60
1997
3
-3.41%
389.20
160.00
1997
4
9.22%
425.08
160.20
1997
5
5.34%
447.77
160.10
1997
6
5.74%
473.45
160.30
1997
7
0.35%
475.10
160.50
1997
8
1.19%
480.76
160.80
1997
9
1.65%
488.67
161.20
1997
10
-1.15%
483.04
161.60
1997
11
2.63%
495.77
161.50
1997
12
0.24%
496.94
161.30
1998
1
6.40%
528.76
161.60
1998
2
5.31%
556.85
161.90
1998
3
3.41%
575.81
162.20
1998
4
-0.22%
574.54
162.50
1998
5
0.12%
575.20
162.80
1998
6
4.47%
600.90
163.00
1998
7
-6.97%
559.01
163.20
1998
8
-4.90%
531.63
163.40
1998
9
1.29%
538.49
163.60
1998
10
10.97%
597.59
164.00
1998
11
4.10%
622.12
164.00
1998
12
5.05%
653.52
163.90
1999
1
-0.07%
653.08
164.30
1999
2
2.92%
672.18
164.50
1999
3
4.25%
700.74
165.00
1999
4
-0.10%
700.05
166.20
1999
5
-0.61%
695.77
166.20
1999
6
4.52%
727.23
166.20
1999
7
-3.77%
699.78
166.70
1999
8
-0.60%
695.60
167.10
1999
9
-1.27%
686.75
167.90
1999
10
7.11%
735.55
168.20
1999
11
2.81%
756.21
168.30
1999
12
-0.12%
755.31
168.30
2000
1
-2.48%
736.59
168.80
2000
2
3.94%
765.62
169.80
2000
3
1.42%
776.53
171.20
2000
4
-2.84%
754.48
171.30
2000
5
3.16%
778.35
171.50
2000
6
0.85%
784.97
172.40
2000
7
0.94%
792.35
172.80
2000
8
-1.08%
783.79
172.80
2000
9
-5.21%
742.92
173.70
2000
10
-0.77%
737.18
174.00
2000
11
-3.32%
712.71
174.10
2000
12
0.46%
715.95
174.00
2001
1
-2.14%
700.66
175.10
2001
2
-9.08%
637.04
175.80
2001
3
0.45%
639.90
176.20
2001
4
6.88%
683.92
176.90
2001
5
-2.39%
667.58
177.70
2001
6
-2.66%
649.82
178.00
2001
7
-2.05%
636.53
177.50
2001
8
-11.25%
564.93
177.50
2001
9
3.18%
582.92
178.30
2001
10
5.05%
612.38
177.70
2001
11
1.47%
621.36
177.40
2001
12
-0.30%
619.51
176.70
Click to show 162 more rows
Remember, returns are based on the average closing price across the entire month. Some losses are offset by dividend returns.
Dollar-cost averaging
Dollar-cost averaging is an alternative to investing the full lump-sum of $100.00 up-front. Instead, the capital is invested over a period of time.
Consider a strategy in which $100.00 was invested in the S&P 500 over a period of no more than 24 months beginning in 1987. This would result in a final amount of $577.40, including dividend reinvestments. In this particular case, dollar-cost average returns are less than the returns of a lump-sum investment (which ends with $619.51).
Year
Month
Contribution ($)
Amount ($)
1987
1
4.16
4.42
1987
2
4.16
8.94
1987
3
4.16
12.98
1987
4
4.16
17.16
1987
5
4.16
22.27
1987
6
4.16
27.24
1987
7
4.16
33.42
1987
8
4.16
36.43
1987
9
4.16
35.77
1987
10
4.16
35.01
1987
11
4.16
38.63
1987
12
4.16
44.60
1988
1
4.16
50.37
1988
2
4.16
56.28
1988
3
4.16
59.89
1988
4
4.16
62.64
1988
5
4.16
70.79
1988
6
4.16
74.71
1988
7
4.16
77.50
1988
8
4.16
83.23
1988
9
4.16
90.70
1988
10
4.16
92.93
1988
11
4.16
99.33
1988
12
4.32
107.28
1989
1
-
110.82
1989
2
-
110.64
1989
3
-
114.59
1989
4
-
119.30
1989
5
-
123.35
1989
6
-
126.80
1989
7
-
132.75
1989
8
-
133.36
1989
9
-
133.74
1989
10
-
131.31
1989
11
-
134.91
1989
12
-
131.92
1990
1
-
128.59
1990
2
-
132.07
1990
3
-
132.33
1990
4
-
137.42
1990
5
-
141.78
1990
6
-
142.02
1990
7
-
130.86
1990
8
-
125.18
1990
9
-
122.28
1990
10
-
125.93
1990
11
-
131.70
1990
12
-
130.80
1991
1
-
145.98
1991
2
-
150.43
1991
3
-
153.82
1991
4
-
153.55
1991
5
-
154.08
1991
6
-
155.28
1991
7
-
159.44
1991
8
-
158.96
1991
9
-
159.25
1991
10
-
159.27
1991
11
-
160.76
1991
12
-
172.59
1992
1
-
171.56
1992
2
-
169.82
1992
3
-
170.27
1992
4
-
173.79
1992
5
-
171.48
1992
6
-
174.76
1992
7
-
176.40
1992
8
-
177.07
1992
9
-
174.98
1992
10
-
179.80
1992
11
-
185.68
1992
12
-
185.95
1993
1
-
189.16
1993
2
-
193.22
1993
3
-
190.63
1993
4
-
192.01
1993
5
-
193.67
1993
6
-
193.79
1993
7
-
197.21
1993
8
-
199.88
1993
9
-
202.36
1993
10
-
202.38
1993
11
-
204.17
1993
12
-
207.72
1994
1
-
207.56
1994
2
-
204.60
1994
3
-
197.76
1994
4
-
199.85
1994
5
-
202.06
1994
6
-
201.02
1994
7
-
207.21
1994
8
-
208.90
1994
9
-
207.98
1994
10
-
207.21
1994
11
-
205.08
1994
12
-
210.11
1995
1
-
218.13
1995
2
-
223.71
1995
3
-
230.91
1995
4
-
238.64
1995
5
-
246.22
1995
6
-
254.96
1995
7
-
256.27
1995
8
-
265.79
1995
9
-
268.22
1995
10
-
274.54
1995
11
-
283.85
1995
12
-
284.31
1996
1
-
301.10
1996
2
-
300.49
1996
3
-
301.08
1996
4
-
308.17
1996
5
-
312.12
1996
6
-
301.26
1996
7
-
310.53
1996
8
-
316.81
1996
9
-
329.87
1996
10
-
346.53
1996
11
-
350.68
1996
12
-
362.11
1997
1
-
377.90
1997
2
-
375.54
1997
3
-
362.75
1997
4
-
396.19
1997
5
-
417.34
1997
6
-
441.27
1997
7
-
442.81
1997
8
-
448.09
1997
9
-
455.46
1997
10
-
450.21
1997
11
-
462.07
1997
12
-
463.17
1998
1
-
492.82
1998
2
-
519.01
1998
3
-
536.68
1998
4
-
535.49
1998
5
-
536.11
1998
6
-
560.07
1998
7
-
521.02
1998
8
-
495.50
1998
9
-
501.90
1998
10
-
556.98
1998
11
-
579.84
1998
12
-
609.11
1999
1
-
608.70
1999
2
-
626.49
1999
3
-
653.12
1999
4
-
652.47
1999
5
-
648.48
1999
6
-
677.81
1999
7
-
652.23
1999
8
-
648.33
1999
9
-
640.08
1999
10
-
685.56
1999
11
-
704.82
1999
12
-
703.98
2000
1
-
686.53
2000
2
-
713.59
2000
3
-
723.75
2000
4
-
703.21
2000
5
-
725.45
2000
6
-
731.62
2000
7
-
738.50
2000
8
-
730.53
2000
9
-
692.43
2000
10
-
687.08
2000
11
-
664.27
2000
12
-
667.30
2001
1
-
653.04
2001
2
-
593.74
2001
3
-
596.41
2001
4
-
637.44
2001
5
-
622.21
2001
6
-
605.66
2001
7
-
593.27
2001
8
-
526.54
2001
9
-
543.31
2001
10
-
570.76
2001
11
-
579.13
2001
12
-
577.40
Click to show 162 more rows
Data Sources
The information on this page is derived from Robert Shiller's book, Irrational Exuberance and the accompanying dataset, as well as the U.S. Bureau of Labor Statistics' monthly CPI logs.
Note that S&P index value for the current quarter is based on a moving average of closing prices, per Robert Shiller's methodology. The inflation data used is based on annual CPI averages.
About the author
Ian Webster is an engineer and data expert based in San Mateo, California. He has worked for Google, NASA, and consulted for governments around the world on data pipelines and data analysis. Disappointed by the lack of clear resources on the impacts of inflation on economic indicators, Ian believes this website serves as a valuable public tool. Ian earned his degree in Computer Science from Dartmouth College.
