If you invested $100000 in the S&P 500 at the beginning of 2000, you would have about $70,749.24 at the end of 2008, assuming you reinvested all dividends. This is a return on investment of -29.25%, or -3.77% per year.
This lump-sum investment does not beat inflation during this period, for an inflation-adjusted return of -43.41% cumulatively, or -6.13% per year.
If you used dollar-cost averaging (monthly) instead of a lump-sum investment, you'd have $76,863.48.
The graph below shows the performance of $100000 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 $100000 is $-29,250.76, or -29.25%. This means by 2008 you would have $70,749.24 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 2000 was 172.200 and the CPI in 2008 was 215.303.
The ratio between these CPIs describes how relative buying power of a dollar has changed over 8 years.
Adjusted for inflation, the $70,749.24 nominal end value of the original $100000 investment would have a real return of roughly $-43,414.54 in 2000 dollars. This means the inflation-adjusted return is -43.41% as opposed to the original -29.25%.
The table below shows the full dataset pertaining to a $100000 investment, including gains and losses over the 108-month period between 2000 and 2008.
Note that data shown is the monthly average closing price. Returns include dividends.
Year
Month
Return (%)
Amount ($)
CPI
2000
1
-2.48%
97,521.92
168.80
2000
2
3.94%
101,365.22
169.80
2000
3
1.42%
102,809.33
171.20
2000
4
-2.84%
99,890.79
171.30
2000
5
3.16%
103,050.81
171.50
2000
6
0.85%
103,927.10
172.40
2000
7
0.94%
104,903.71
172.80
2000
8
-1.08%
103,771.12
172.80
2000
9
-5.21%
98,360.25
173.70
2000
10
-0.77%
97,600.36
174.00
2000
11
-3.32%
94,359.95
174.10
2000
12
0.46%
94,789.30
174.00
2001
1
-2.14%
92,764.35
175.10
2001
2
-9.08%
84,341.44
175.80
2001
3
0.45%
84,719.88
176.20
2001
4
6.88%
90,548.04
176.90
2001
5
-2.39%
88,385.16
177.70
2001
6
-2.66%
86,033.91
178.00
2001
7
-2.05%
84,273.80
177.50
2001
8
-11.25%
74,795.25
177.50
2001
9
3.18%
77,176.76
178.30
2001
10
5.05%
81,076.61
177.70
2001
11
1.47%
82,265.23
177.40
2001
12
-0.30%
82,020.34
176.70
2002
1
-3.35%
79,270.38
177.10
2002
2
4.95%
83,190.52
177.80
2002
3
-3.51%
80,266.85
178.80
2002
4
-2.82%
78,003.02
179.80
2002
5
-5.92%
73,384.50
179.80
2002
6
-10.76%
65,489.43
179.90
2002
7
1.14%
66,235.21
180.10
2002
8
-4.76%
63,083.92
180.70
2002
9
-1.37%
62,221.54
181.00
2002
10
6.63%
66,344.07
181.30
2002
11
-1.04%
65,657.37
181.30
2002
12
-0.22%
65,511.27
180.90
2003
1
-6.41%
61,308.83
181.70
2003
2
1.31%
62,110.69
183.10
2003
3
5.29%
65,393.77
184.20
2003
4
5.31%
68,867.63
183.80
2003
5
5.70%
72,795.96
183.50
2003
6
0.60%
73,229.75
183.70
2003
7
-0.17%
73,107.96
183.90
2003
8
3.16%
75,419.03
184.60
2003
9
2.03%
76,948.40
185.20
2003
10
1.21%
77,879.93
185.00
2003
11
3.06%
80,266.02
184.50
2003
12
4.93%
84,227.12
184.30
2004
1
1.09%
85,142.38
185.20
2004
2
-1.57%
83,809.74
186.20
2004
3
0.97%
84,621.13
187.40
2004
4
-2.56%
82,451.23
188.00
2004
5
2.86%
84,807.42
189.10
2004
6
-2.24%
82,908.77
189.70
2004
7
-1.39%
81,758.35
189.40
2004
8
2.78%
84,033.38
189.50
2004
9
0.10%
84,119.59
189.90
2004
10
4.77%
88,135.37
190.90
2004
11
2.73%
90,539.22
191.00
2004
12
-1.35%
89,317.64
190.30
2005
1
1.68%
90,819.26
190.70
2005
2
-0.26%
90,587.14
191.80
2005
3
-2.41%
88,404.97
193.30
2005
4
1.34%
89,585.94
194.60
2005
5
2.18%
91,539.54
194.40
2005
6
1.81%
93,194.38
194.50
2005
7
0.31%
93,483.30
195.40
2005
8
0.28%
93,744.77
196.40
2005
9
-2.62%
91,284.70
198.80
2005
10
3.96%
94,900.98
199.20
2005
11
2.14%
96,935.78
197.60
2005
12
1.47%
98,357.61
196.80
2006
1
-0.02%
98,341.24
198.30
2006
2
1.49%
99,802.73
198.70
2006
3
0.80%
100,599.48
199.80
2006
4
-0.79%
99,808.13
201.50
2006
5
-2.71%
97,107.53
202.50
2006
6
0.72%
97,806.74
202.90
2006
7
2.29%
100,048.24
203.50
2006
8
2.53%
102,580.63
203.90
2006
9
3.62%
106,289.86
202.90
2006
10
2.00%
108,417.40
201.80
2006
11
2.15%
110,746.50
201.50
2006
12
0.69%
111,513.78
201.80
2007
1
1.60%
113,293.59
202.42
2007
2
-2.47%
110,490.83
203.50
2007
3
4.18%
115,109.63
205.35
2007
4
3.39%
119,013.87
206.69
2007
5
0.34%
119,424.35
207.95
2007
6
0.57%
120,110.59
208.35
2007
7
-4.20%
115,064.61
208.30
2007
8
3.07%
118,602.55
207.92
2007
9
2.99%
122,150.71
208.49
2007
10
-4.81%
116,279.76
208.94
2007
11
1.24%
117,719.56
210.18
2007
12
-6.64%
109,908.64
210.04
2008
1
-1.56%
108,189.71
211.08
2008
2
-2.63%
105,347.96
211.69
2008
3
4.24%
109,818.71
213.53
2008
4
2.56%
112,632.93
214.82
2008
5
-4.25%
107,849.88
216.63
2008
6
-6.08%
101,294.26
218.82
2008
7
2.11%
103,432.11
219.96
2008
8
-4.85%
98,418.20
219.09
2008
9
-20.19%
78,544.04
218.78
2008
10
-8.61%
71,785.05
216.57
2008
11
-0.35%
71,532.93
212.43
2008
12
-1.10%
70,749.24
210.23
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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 $100,000.00 up-front. Instead, the capital is invested over a period of time.
Consider a strategy in which $100,000.00 was invested in the S&P 500 over a period of no more than 24 months beginning in 2000. This would result in a final amount of $76,863.48, including dividend reinvestments. In this particular case, dollar-cost average returns are greater than the returns of a lump-sum investment (which ends with $70,749.24).
Year
Month
Contribution ($)
Amount ($)
2000
1
4166.66
4,059.34
2000
2
4166.66
8,545.99
2000
3
4166.66
12,889.73
2000
4
4166.66
16,568.22
2000
5
4166.66
21,386.73
2000
6
4166.66
25,766.72
2000
7
4166.66
30,210.75
2000
8
4166.66
34,002.41
2000
9
4166.66
36,174.98
2000
10
4166.66
40,025.90
2000
11
4166.66
42,721.22
2000
12
4166.66
47,096.98
2001
1
4166.66
50,164.32
2001
2
4166.66
49,393.50
2001
3
4166.66
53,795.81
2001
4
4166.66
61,945.27
2001
5
4166.66
64,528.43
2001
6
4166.66
66,863.24
2001
7
4166.66
69,572.22
2001
8
4166.66
65,440.59
2001
9
4166.66
71,818.34
2001
10
4166.66
79,819.56
2001
11
4166.66
85,212.66
2001
12
4166.82
89,108.63
2002
1
-
86,121.02
2002
2
-
90,379.94
2002
3
-
87,203.60
2002
4
-
84,744.14
2002
5
-
79,726.47
2002
6
-
71,149.10
2002
7
-
71,959.34
2002
8
-
68,535.71
2002
9
-
67,598.79
2002
10
-
72,077.60
2002
11
-
71,331.56
2002
12
-
71,172.83
2003
1
-
66,607.21
2003
2
-
67,478.37
2003
3
-
71,045.18
2003
4
-
74,819.25
2003
5
-
79,087.08
2003
6
-
79,558.36
2003
7
-
79,426.03
2003
8
-
81,936.83
2003
9
-
83,598.37
2003
10
-
84,610.40
2003
11
-
87,202.70
2003
12
-
91,506.12
2004
1
-
92,500.49
2004
2
-
91,052.67
2004
3
-
91,934.19
2004
4
-
89,576.76
2004
5
-
92,136.57
2004
6
-
90,073.84
2004
7
-
88,824.00
2004
8
-
91,295.64
2004
9
-
91,389.31
2004
10
-
95,752.14
2004
11
-
98,363.72
2004
12
-
97,036.58
2005
1
-
98,667.97
2005
2
-
98,415.78
2005
3
-
96,045.03
2005
4
-
97,328.06
2005
5
-
99,450.49
2005
6
-
101,248.35
2005
7
-
101,562.24
2005
8
-
101,846.30
2005
9
-
99,173.63
2005
10
-
103,102.43
2005
11
-
105,313.09
2005
12
-
106,857.79
2006
1
-
106,840.01
2006
2
-
108,427.80
2006
3
-
109,293.41
2006
4
-
108,433.67
2006
5
-
105,499.68
2006
6
-
106,259.32
2006
7
-
108,694.53
2006
8
-
111,445.77
2006
9
-
115,475.55
2006
10
-
117,786.96
2006
11
-
120,317.34
2006
12
-
121,150.93
2007
1
-
123,084.56
2007
2
-
120,039.58
2007
3
-
125,057.54
2007
4
-
129,299.19
2007
5
-
129,745.14
2007
6
-
130,490.68
2007
7
-
125,008.63
2007
8
-
128,852.32
2007
9
-
132,707.11
2007
10
-
126,328.80
2007
11
-
127,893.03
2007
12
-
119,407.07
2008
1
-
117,539.59
2008
2
-
114,452.25
2008
3
-
119,309.38
2008
4
-
122,366.80
2008
5
-
117,170.40
2008
6
-
110,048.23
2008
7
-
112,370.83
2008
8
-
106,923.62
2008
9
-
85,331.91
2008
10
-
77,988.80
2008
11
-
77,714.89
2008
12
-
76,863.48
Click to show 90 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.
