DCA Timing Optimization Analysis
S&P 500 Investment Day Performance Study
This study analyzes the historical performance of Dollar Cost Averaging based on investment timing. Using actual S&P 500 data, we examine whether specific days of the month or week have consistently produced superior returns, helping investors optimize their systematic investment schedules.
Key Findings Summary
Optimal Day of Month
Optimal Day of Week
Statistical Analysis
Day of Month Performance Analysis
Investment performance by calendar day (ranked by total return)
| Rank | Day of Month | Investments | Total Invested | Avg. Cost/Share | Final Value | Total Return |
|---|---|---|---|---|---|---|
| #1 | 19th | 105 | $10,500 | $2521.78 | $25,151.14 | +139.53% |
| #2 | 7th | 108 | $10,800 | $2524.49 | $25,841.93 | +139.28% |
| #3 | 5th | 107 | $10,700 | $2525.80 | $25,589.39 | +139.15% |
| #4 | 4th | 99 | $9,900 | $2527.02 | $23,664.77 | +139.04% |
| #5 | 24th | 108 | $10,800 | $2527.91 | $25,807.03 | +138.95% |
| #6 | 11th | 111 | $11,100 | $2530.10 | $26,500.87 | +138.75% |
| #7 | 2nd | 105 | $10,500 | $2531.41 | $25,055.39 | +138.62% |
| #8 | 25th | 97 | $9,700 | $2535.51 | $23,108.98 | +138.24% |
| #9 | 13th | 113 | $11,300 | $2536.78 | $26,907.32 | +138.12% |
| #10 | 10th | 110 | $11,000 | $2538.29 | $26,177.37 | +137.98% |
| #11 | 9th | 110 | $11,000 | $2538.34 | $26,176.91 | +137.97% |
| #12 | 20th | 106 | $10,600 | $2539.14 | $25,217.01 | +137.90% |
| #13 | 14th | 110 | $11,000 | $2541.21 | $26,147.29 | +137.70% |
| #14 | 6th | 111 | $11,100 | $2541.84 | $26,378.49 | +137.64% |
| #15 | 17th | 108 | $10,800 | $2541.91 | $25,664.81 | +137.64% |
| #16 | 12th | 111 | $11,100 | $2544.78 | $26,347.98 | +137.37% |
| #17 | 15th | 107 | $10,700 | $2547.77 | $25,368.72 | +137.09% |
| #18 | 23th | 109 | $10,900 | $2549.01 | $25,830.38 | +136.98% |
| #19 | 27th | 109 | $10,900 | $2548.92 | $25,831.25 | +136.98% |
| #20 | 21th | 108 | $10,800 | $2550.91 | $25,574.26 | +136.80% |
| #21 | 26th | 106 | $10,600 | $2555.00 | $25,060.48 | +136.42% |
| #22 | 3rd | 106 | $10,600 | $2555.73 | $25,053.32 | +136.35% |
| #23 | 16th | 108 | $10,800 | $2557.05 | $25,512.9 | +136.23% |
| #24 | 28th | 106 | $10,600 | $2559.68 | $25,014.69 | +135.99% |
| #25 | 30th | 99 | $9,900 | $2559.97 | $23,360.16 | +135.96% |
| #26 | 8th | 112 | $11,200 | $2565.57 | $26,369.91 | +135.45% |
| #27 | 1st | 101 | $10,100 | $2565.76 | $23,778.25 | +135.43% |
| #28 | 18th | 106 | $10,600 | $2567.66 | $24,936.93 | +135.25% |
| #29 | 29th | 101 | $10,100 | $2568.32 | $23,754.56 | +135.19% |
| #30 | 31th | 66 | $6,600 | $2578.60 | $15,460.92 | +134.26% |
| #31 | 22th | 110 | $11,000 | $2599.84 | $25,557.66 | +132.34% |
Day of Week Performance Analysis
Investment performance by weekday (ranked by total return)
| Rank | Day of Week | Investments | Total Invested | Avg. Cost/Share | Final Value | Total Return |
|---|---|---|---|---|---|---|
| #1 | Monday | 613 | $61,300 | $2536.76 | $145,967.4 | +138.12% |
| #2 | Wednesday | 669 | $66,900 | $2545.26 | $158,770.41 | +137.32% |
| #3 | Thursday | 660 | $66,000 | $2545.63 | $156,611.32 | +137.29% |
| #4 | Friday | 658 | $65,800 | $2550.90 | $155,814.43 | +136.80% |
| #5 | Tuesday | 672 | $67,200 | $2554.90 | $158,880.19 | +136.43% |
Analysis Interpretation
Based on 3,273 trading days from 2012-02-01 to 2025-01-31, this analysis reveals the historical impact of investment timing on Dollar Cost Averaging performance.
Day of Month Findings: The 19th of the month historically produced the highest returns (139.53%), while the 22th produced the lowest (132.34%). The standard deviation of 1.61% indicates modest variation in outcomes based on monthly timing.
Day of Week Findings: Monday investments historically outperformed (138.12%), while Tuesday showed the weakest performance (136.43%). The weekly standard deviation of 0.57% suggests limited differences between weekday investment timing.
STATISTICAL DISCLAIMER
While these patterns exist in historical data, the differences may not be statistically significant enough to reliably predict future performance. Market timing effects are generally considered less important than consistent investment discipline and long-term commitment to a DCA strategy.
METHODOLOGY NOTE
Analysis assumes $100 investments on specified days, with dividend reinvestment and no transaction costs. Days falling on weekends or holidays are adjusted to the next trading day. Results exclude taxes and fees.
Data source: MacroTrends S&P 500 Historical Data