Lump Sum vs. Dollar-Cost Averaging
Should you invest all at once or spread it out? Tested against every historical S&P 500 window from 1928 to present, not just a formula.
$
%
yrs
Lump Sum: Median Historical
$385,073
across 78 historical windows
DCA over 12 months: Median
$402,998
avg $2,606 HYSA earned
DCA Median Edge
$17,925
median outcome difference
Lump Sum Wins
68%
of 78 historical 20-year windows
Side-by-Side (Historical Medians)
Lump Sum
Median final value
$385,073
Mean final value
$478,570
Std deviation
$268,158
HYSA earnings
$0 (invested day 1)
DCA over 12 months
Median final value
$402,998
Mean final value
$459,695
Std deviation
$251,100
Avg HYSA earnings
$2,606
⚠️ DCA has a higher median outcome in this scenario (32% of historical windows). This is partly driven by the HYSA rate keeping uninvested cash productive. Note that lump sum still wins in 68% of windows — and has a higher mean ($478,570 vs $459,695) — because a handful of exceptional bull-market windows pull the average up. Whether median or mean is more relevant to your decision depends on how you think about risk.
Every Historical 20-Year Window (1928–2025)
| Start Year | End Year | Lump Sum | DCA (12mo) | Winner | Edge |
|---|---|---|---|---|---|
| 1928 | 1948 | $149,573 | $130,796 | Lump Sum | +$18,777 |
| 1929 | 1949 | $123,790 | $130,854 | DCA | -$7,064 |
| 1930 | 1950 | $172,707 | $196,830 | DCA | -$24,123 |
| 1931 | 1951 | $271,752 | $342,366 | DCA | -$70,614 |
| 1932 | 1952 | $508,326 | $530,406 | DCA | -$22,080 |
| 1933 | 1953 | $547,148 | $458,770 | Lump Sum | +$88,378 |
| 1934 | 1954 | $541,423 | $546,733 | DCA | -$5,310 |
| 1935 | 1955 | $711,589 | $606,256 | Lump Sum | +$105,333 |
| 1936 | 1956 | $522,120 | $463,595 | Lump Sum | +$58,524 |
| 1937 | 1957 | $356,127 | $428,161 | DCA | -$72,034 |
| 1938 | 1958 | $732,947 | $656,056 | Lump Sum | +$76,892 |
| 1939 | 1959 | $632,842 | $636,729 | DCA | -$3,887 |
| 1940 | 1960 | $638,563 | $669,383 | DCA | -$30,820 |
| 1941 | 1961 | $883,134 | $928,659 | DCA | -$45,525 |
| 1942 | 1962 | $896,247 | $832,354 | Lump Sum | +$63,893 |
| 1943 | 1963 | $921,405 | $836,854 | Lump Sum | +$84,551 |
| 1944 | 1964 | $856,339 | $795,229 | Lump Sum | +$61,110 |
| 1945 | 1965 | $808,288 | $710,721 | Lump Sum | +$97,567 |
| 1946 | 1966 | $543,385 | $564,997 | DCA | -$21,612 |
| 1947 | 1967 | $720,942 | $705,883 | Lump Sum | +$15,059 |
| 1948 | 1968 | $754,739 | $739,232 | Lump Sum | +$15,507 |
| 1949 | 1969 | $659,136 | $616,252 | Lump Sum | +$42,883 |
| 1950 | 1970 | $582,841 | $522,248 | Lump Sum | +$60,593 |
| 1951 | 1971 | $513,696 | $471,508 | Lump Sum | +$42,188 |
| 1952 | 1972 | $496,207 | $464,497 | Lump Sum | +$31,709 |
| 1953 | 1973 | $364,989 | $368,908 | DCA | -$3,919 |
| 1954 | 1974 | $278,284 | $235,654 | Lump Sum | +$42,630 |
| 1955 | 1975 | $252,732 | $227,334 | Lump Sum | +$25,398 |
| 1956 | 1976 | $239,144 | $235,113 | Lump Sum | +$4,031 |
| 1957 | 1977 | $210,164 | $223,121 | DCA | -$12,957 |
| 1958 | 1978 | $247,962 | $215,262 | Lump Sum | +$32,701 |
| 1959 | 1979 | $206,241 | $198,842 | Lump Sum | +$7,398 |
| 1960 | 1980 | $240,990 | $243,090 | DCA | -$2,100 |
| 1961 | 1981 | $229,403 | $209,445 | Lump Sum | +$19,959 |
| 1962 | 1982 | $218,001 | $229,637 | DCA | -$11,635 |
| 1963 | 1983 | $289,383 | $267,252 | Lump Sum | +$22,131 |
| 1964 | 1984 | $251,466 | $237,795 | Lump Sum | +$13,672 |
| 1965 | 1985 | $282,241 | $270,671 | Lump Sum | +$11,570 |
| 1966 | 1986 | $297,155 | $313,897 | DCA | -$16,742 |
| 1967 | 1987 | $347,262 | $318,824 | Lump Sum | +$28,438 |
| 1968 | 1988 | $326,903 | $314,964 | Lump Sum | +$11,939 |
| 1969 | 1989 | $385,694 | $403,218 | DCA | -$17,524 |
| 1970 | 1990 | $406,673 | $402,778 | Lump Sum | +$3,895 |
| 1971 | 1991 | $508,194 | $481,726 | Lump Sum | +$26,468 |
| 1972 | 1992 | $478,788 | $446,402 | Lump Sum | +$32,386 |
| 1973 | 1993 | $444,187 | $478,512 | DCA | -$34,325 |
| 1974 | 1994 | $522,255 | $598,031 | DCA | -$75,776 |
| 1975 | 1995 | $941,301 | $824,161 | Lump Sum | +$117,141 |
| 1976 | 1996 | $848,073 | $775,225 | Lump Sum | +$72,848 |
| 1977 | 1997 | $914,253 | $945,730 | DCA | -$31,477 |
| 1978 | 1998 | $1,252,159 | $1,220,169 | Lump Sum | +$31,990 |
| 1979 | 1999 | $1,421,249 | $1,323,764 | Lump Sum | +$97,486 |
| 1980 | 2000 | $1,101,211 | $980,585 | Lump Sum | +$120,626 |
| 1981 | 2001 | $746,050 | $764,155 | DCA | -$18,106 |
| 1982 | 2002 | $611,787 | $566,769 | Lump Sum | +$45,019 |
| 1983 | 2003 | $654,212 | $601,720 | Lump Sum | +$52,492 |
| 1984 | 2004 | $595,184 | $582,236 | Lump Sum | +$12,948 |
| 1985 | 2005 | $588,332 | $525,521 | Lump Sum | +$62,812 |
| 1986 | 2006 | $521,606 | $486,745 | Lump Sum | +$34,860 |
| 1987 | 2007 | $466,106 | $457,096 | Lump Sum | +$9,010 |
| 1988 | 2008 | $285,512 | $269,656 | Lump Sum | +$15,855 |
| 1989 | 2009 | $309,007 | $276,996 | Lump Sum | +$32,010 |
| 1990 | 2010 | $271,548 | $277,825 | DCA | -$6,277 |
| 1991 | 2011 | $285,556 | $257,000 | Lump Sum | +$28,555 |
| 1992 | 2012 | $255,026 | $249,578 | Lump Sum | +$5,447 |
| 1993 | 2013 | $312,638 | $302,288 | Lump Sum | +$10,350 |
| 1994 | 2014 | $322,750 | $323,381 | DCA | -$631 |
| 1995 | 2015 | $322,846 | $283,799 | Lump Sum | +$39,047 |
| 1996 | 2016 | $264,172 | $243,934 | Lump Sum | +$20,238 |
| 1997 | 2017 | $262,012 | $233,576 | Lump Sum | +$28,435 |
| 1998 | 2018 | $189,367 | $172,124 | Lump Sum | +$17,243 |
| 1999 | 2019 | $193,331 | $180,224 | Lump Sum | +$13,106 |
| 2000 | 2020 | $188,750 | $199,685 | DCA | -$10,936 |
| 2001 | 2021 | $265,634 | $283,965 | DCA | -$18,331 |
| 2002 | 2022 | $247,410 | $279,852 | DCA | -$32,443 |
| 2003 | 2023 | $371,777 | $335,460 | Lump Sum | +$36,317 |
| 2004 | 2024 | $361,785 | $348,195 | Lump Sum | +$13,589 |
| 2005 | 2025 | $384,451 | $378,984 | Lump Sum | +$5,468 |