If you invested $100 in the S&P 500 at the beginning of 1929, you would have about $90.17 at the end of 1942, assuming you reinvested all dividends. This is a return on investment of -9.83%, or -0.74% per year.
This lump-sum investment does not beat inflation during this period, for an inflation-adjusted return of -5.40% cumulatively, or -0.40% per year.
If you used dollar-cost averaging (monthly) instead of a lump-sum investment, you'd have $94.09.
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 $-9.83, or -9.83%. This means by 1942 you would have $90.17 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 1929 was 17.100 and the CPI in 1942 was 16.300.
The ratio between these CPIs describes how relative buying power of a dollar has changed over 13 years.
Adjusted for inflation, the $90.17 nominal end value of the original $100 investment would have a real return of roughly $-5.40 in 1929 dollars. This means the inflation-adjusted return is -5.40% as opposed to the original -9.83%.
The table below shows the full dataset pertaining to a $100 investment, including gains and losses over the 168-month period between 1929 and 1942.
Note that data shown is the monthly average closing price. Returns include dividends.
Year
Month
Return (%)
Amount ($)
CPI
1929
1
0.81%
100.81
17.10
1929
2
2.05%
102.88
17.10
1929
3
-0.30%
102.57
17.00
1929
4
1.80%
104.41
16.90
1929
5
2.20%
106.71
17.00
1929
6
9.20%
116.53
17.10
1929
7
5.96%
123.47
17.30
1929
8
4.24%
128.71
17.30
1929
9
-10.32%
115.42
17.30
1929
10
-26.19%
85.19
17.30
1929
11
4.37%
88.92
17.30
1929
12
1.83%
90.54
17.20
1930
1
6.64%
96.55
17.10
1930
2
4.12%
100.53
17.00
1930
3
6.69%
107.25
16.90
1930
4
-5.65%
101.19
17.00
1930
5
-9.77%
91.31
16.90
1930
6
-1.76%
89.70
16.80
1930
7
-0.90%
88.89
16.60
1930
8
0.34%
89.20
16.50
1930
9
-13.37%
77.27
16.60
1930
10
-6.80%
72.02
16.50
1930
11
-6.19%
67.56
16.40
1930
12
3.56%
69.97
16.10
1931
1
8.14%
75.66
15.90
1931
2
2.38%
77.46
15.70
1931
3
-9.08%
70.43
15.60
1931
4
-9.16%
63.98
15.50
1931
5
-2.68%
62.26
15.30
1931
6
3.86%
64.66
15.10
1931
7
-2.49%
63.06
15.10
1931
8
-14.37%
54.00
15.10
1931
9
-12.75%
47.11
15.00
1931
10
2.05%
48.08
14.90
1931
11
-18.10%
39.38
14.70
1931
12
-0.85%
39.04
14.60
1932
1
-0.05%
39.03
14.30
1932
2
1.14%
39.47
14.10
1932
3
-23.22%
30.30
14.00
1932
4
-11.31%
26.87
13.90
1932
5
-12.39%
23.54
13.70
1932
6
6.18%
25.00
13.60
1932
7
51.35%
37.84
13.60
1932
8
10.37%
41.76
13.50
1932
9
-13.22%
36.24
13.40
1932
10
-0.34%
36.12
13.30
1932
11
-2.64%
35.17
13.20
1932
12
4.57%
36.77
13.10
1933
1
-11.27%
32.63
12.90
1933
2
0.33%
32.74
12.70
1933
3
11.24%
36.42
12.60
1933
4
29.32%
47.10
12.60
1933
5
17.58%
55.38
12.60
1933
6
8.46%
60.07
12.70
1933
7
-4.64%
57.28
13.10
1933
8
-0.48%
57.00
13.20
1933
9
-9.38%
51.66
13.20
1933
10
2.80%
53.10
13.20
1933
11
2.32%
54.34
13.20
1933
12
6.08%
57.64
13.20
1934
1
7.75%
62.11
13.20
1934
2
-4.80%
59.13
13.30
1934
3
2.02%
60.32
13.30
1934
4
-9.83%
54.39
13.30
1934
5
1.70%
55.32
13.30
1934
6
-4.36%
52.91
13.40
1934
7
-3.51%
51.05
13.40
1934
8
-2.01%
50.03
13.40
1934
9
1.21%
50.63
13.60
1934
10
3.21%
52.26
13.50
1934
11
1.06%
52.81
13.50
1934
12
0.40%
53.02
13.40
1935
1
-2.62%
51.64
13.60
1935
2
-5.93%
48.57
13.70
1935
3
7.94%
52.43
13.70
1935
4
8.27%
56.76
13.80
1935
5
4.17%
59.13
13.80
1935
6
5.60%
62.44
13.70
1935
7
7.10%
66.88
13.70
1935
8
2.43%
68.51
13.70
1935
9
2.99%
70.55
13.70
1935
10
9.71%
77.40
13.70
1935
11
0.29%
77.63
13.80
1935
12
5.82%
82.15
13.80
1936
1
6.03%
87.10
13.80
1936
2
2.41%
89.21
13.80
1936
3
0.41%
89.58
13.70
1936
4
-5.02%
85.08
13.70
1936
5
4.57%
88.97
13.70
1936
6
6.23%
94.52
13.80
1936
7
2.30%
96.69
13.90
1936
8
1.44%
98.08
14.00
1936
9
5.55%
103.53
14.00
1936
10
3.10%
106.74
14.00
1936
11
-1.40%
105.25
14.00
1936
12
3.46%
108.89
14.00
1937
1
3.30%
112.48
14.10
1937
2
0.23%
112.74
14.10
1937
3
-5.62%
106.40
14.20
1937
4
-4.09%
102.05
14.30
1937
5
-3.34%
98.64
14.40
1937
6
6.39%
104.95
14.40
1937
7
1.44%
106.46
14.50
1937
8
-13.76%
91.81
14.50
1937
9
-14.10%
78.86
14.60
1937
10
-8.27%
72.35
14.60
1937
11
-1.02%
71.61
14.50
1937
12
3.24%
73.93
14.40
1938
1
-1.80%
72.59
14.20
1938
2
-6.02%
68.22
14.10
1938
3
-3.44%
65.88
14.10
1938
4
1.56%
66.90
14.20
1938
5
2.93%
68.86
14.10
1938
6
20.49%
82.97
14.10
1938
7
1.06%
83.85
14.10
1938
8
-4.08%
80.42
14.10
1938
9
11.62%
89.77
14.10
1938
10
0.47%
90.18
14.00
1938
11
-2.55%
87.88
14.00
1938
12
-1.16%
86.86
14.00
1939
1
-0.46%
86.47
14.00
1939
2
0.27%
86.70
13.90
1939
3
-12.24%
76.08
13.90
1939
4
4.10%
79.20
13.80
1939
5
2.17%
80.92
13.80
1939
6
2.84%
83.21
13.80
1939
7
-1.07%
82.33
13.80
1939
8
11.06%
91.43
13.80
1939
9
1.38%
92.69
14.10
1939
10
-1.41%
91.39
14.00
1939
11
-1.97%
89.58
14.00
1939
12
-0.15%
89.45
14.00
1940
1
-0.23%
89.25
13.90
1940
2
-0.15%
89.12
14.00
1940
3
1.42%
90.38
14.00
1940
4
-13.34%
78.33
14.00
1940
5
-8.09%
71.99
14.00
1940
6
3.87%
74.77
14.10
1940
7
2.65%
76.75
14.00
1940
8
4.76%
80.40
14.00
1940
9
1.47%
81.58
14.00
1940
10
2.85%
83.91
14.00
1940
11
-3.59%
80.90
14.00
1940
12
0.72%
81.48
14.10
1941
1
-5.72%
76.81
14.10
1941
2
1.18%
77.72
14.10
1941
3
-2.55%
75.74
14.20
1941
4
-1.59%
74.54
14.30
1941
5
4.11%
77.60
14.40
1941
6
5.71%
82.03
14.70
1941
7
0.08%
82.09
14.70
1941
8
0.86%
82.80
14.90
1941
9
-3.43%
79.96
15.10
1941
10
-4.08%
76.69
15.30
1941
11
-5.88%
72.18
15.40
1941
12
2.62%
74.07
15.50
1942
1
-2.48%
72.23
15.70
1942
2
-4.76%
68.79
15.80
1942
3
-3.45%
66.42
16.00
1942
4
1.87%
67.66
16.10
1942
5
5.75%
71.55
16.30
1942
6
4.38%
74.68
16.30
1942
7
0.05%
74.72
16.40
1942
8
1.66%
75.96
16.50
1942
9
7.97%
82.01
16.50
1942
10
2.15%
83.78
16.70
1942
11
1.06%
84.66
16.80
1942
12
6.50%
90.17
16.90
Click to show 150 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 1929. This would result in a final amount of $94.09, including dividend reinvestments. In this particular case, dollar-cost average returns are greater than the returns of a lump-sum investment (which ends with $90.17).
Year
Month
Contribution ($)
Amount ($)
1929
1
4.16
4.18
1929
2
4.16
8.50
1929
3
4.16
12.61
1929
4
4.16
17.06
1929
5
4.16
21.67
1929
6
4.16
28.20
1929
7
4.16
34.28
1929
8
4.16
40.06
1929
9
4.16
39.64
1929
10
4.16
32.32
1929
11
4.16
38.06
1929
12
4.16
42.97
1930
1
4.16
50.24
1930
2
4.16
56.63
1930
3
4.16
64.84
1930
4
4.16
65.09
1930
5
4.16
62.47
1930
6
4.16
65.44
1930
7
4.16
68.96
1930
8
4.16
73.36
1930
9
4.16
67.14
1930
10
4.16
66.43
1930
11
4.16
66.20
1930
12
4.32
73.01
1931
1
-
78.95
1931
2
-
80.83
1931
3
-
73.49
1931
4
-
66.76
1931
5
-
64.97
1931
6
-
67.48
1931
7
-
65.80
1931
8
-
56.34
1931
9
-
49.16
1931
10
-
50.17
1931
11
-
41.09
1931
12
-
40.74
1932
1
-
40.72
1932
2
-
41.19
1932
3
-
31.62
1932
4
-
28.04
1932
5
-
24.57
1932
6
-
26.09
1932
7
-
39.48
1932
8
-
43.58
1932
9
-
37.82
1932
10
-
37.69
1932
11
-
36.70
1932
12
-
38.37
1933
1
-
34.05
1933
2
-
34.16
1933
3
-
38.00
1933
4
-
49.15
1933
5
-
57.79
1933
6
-
62.68
1933
7
-
59.77
1933
8
-
59.48
1933
9
-
53.90
1933
10
-
55.41
1933
11
-
56.70
1933
12
-
60.15
1934
1
-
64.81
1934
2
-
61.70
1934
3
-
62.94
1934
4
-
56.76
1934
5
-
57.73
1934
6
-
55.21
1934
7
-
53.27
1934
8
-
52.20
1934
9
-
52.83
1934
10
-
54.53
1934
11
-
55.11
1934
12
-
55.33
1935
1
-
53.88
1935
2
-
50.68
1935
3
-
54.71
1935
4
-
59.23
1935
5
-
61.70
1935
6
-
65.16
1935
7
-
69.79
1935
8
-
71.48
1935
9
-
73.62
1935
10
-
80.77
1935
11
-
81.00
1935
12
-
85.72
1936
1
-
90.89
1936
2
-
93.08
1936
3
-
93.47
1936
4
-
88.78
1936
5
-
92.84
1936
6
-
98.63
1936
7
-
100.89
1936
8
-
102.35
1936
9
-
108.03
1936
10
-
111.38
1936
11
-
109.82
1936
12
-
113.62
1937
1
-
117.37
1937
2
-
117.64
1937
3
-
111.02
1937
4
-
106.49
1937
5
-
102.93
1937
6
-
109.51
1937
7
-
111.09
1937
8
-
95.80
1937
9
-
82.29
1937
10
-
75.49
1937
11
-
74.72
1937
12
-
77.14
1938
1
-
75.75
1938
2
-
71.19
1938
3
-
68.74
1938
4
-
69.81
1938
5
-
71.86
1938
6
-
86.58
1938
7
-
87.49
1938
8
-
83.92
1938
9
-
93.67
1938
10
-
94.10
1938
11
-
91.70
1938
12
-
90.64
1939
1
-
90.22
1939
2
-
90.46
1939
3
-
79.39
1939
4
-
82.64
1939
5
-
84.44
1939
6
-
86.83
1939
7
-
85.91
1939
8
-
95.40
1939
9
-
96.72
1939
10
-
95.36
1939
11
-
93.48
1939
12
-
93.34
1940
1
-
93.13
1940
2
-
92.99
1940
3
-
94.31
1940
4
-
81.73
1940
5
-
75.11
1940
6
-
78.02
1940
7
-
80.09
1940
8
-
83.90
1940
9
-
85.13
1940
10
-
87.55
1940
11
-
84.41
1940
12
-
85.02
1941
1
-
80.15
1941
2
-
81.10
1941
3
-
79.03
1941
4
-
77.78
1941
5
-
80.97
1941
6
-
85.60
1941
7
-
85.66
1941
8
-
86.40
1941
9
-
83.43
1941
10
-
80.03
1941
11
-
75.32
1941
12
-
77.29
1942
1
-
75.37
1942
2
-
71.78
1942
3
-
69.30
1942
4
-
70.60
1942
5
-
74.66
1942
6
-
77.93
1942
7
-
77.97
1942
8
-
79.26
1942
9
-
85.58
1942
10
-
87.42
1942
11
-
88.34
1942
12
-
94.09
Click to show 150 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.
