DCA FINANCE / Research
How the starting date changed 30-day Bitcoin purchase results
Every complete 30-day window in one verified BTC snapshot: daily purchases versus one upfront investment with an equal budget. Results, chart, methodology and calculation exports.
Evgeniy Volkov ·
One budget, every available starting date
Within the saved Bitcoin series from Sep 5, 2026 to Nov 4, 2026 UTC, we take all 32 complete 30-day windows. Each compares 30 daily purchases of $10.00 with one $300.00 purchase at the start. The full budget is available on the first day of each window.
This period was selected because a verified snapshot already existed, not to demonstrate a winning strategy. No eligible starting date inside it is omitted. Fees, taxes and interest on uninvested cash are excluded.
What changed when the starting date moved
DCA finishes with a higher value in 15 windows and lump sum in 17; there are 0 ties. These are counts of specific historical results, not estimates of future winning probabilities.
Adjacent windows share 29 days, so the results are dependent. They are not 32 independent experiments. This short market segment cannot establish which strategy is better over many years.
| Purchase strategy | Minimum | Median | Maximum |
|---|---|---|---|
| DCA | -6.79% | -1.78% | +6.77% |
| Lump sum | -10.03% | +0.97% | +8.98% |
Window return is (final value / total budget − 1) × 100%. It is neither annualized return nor XIRR. Each strategy’s median is calculated across all its windows separately.
Final value by window starting date
Each point is a separate 30-day calculation. The x-axis shows starting dates, not the path of one portfolio over time. Connecting lines help compare adjacent windows.
Chart values by starting date
| Date | DCA | Lump sum |
|---|---|---|
| 2026-09-05 | $320.32 | $325.40 |
| 2026-09-06 | $317.62 | $322.91 |
| 2026-09-07 | $315.43 | $319.42 |
| 2026-09-08 | $306.20 | $315.56 |
| 2026-09-09 | $300.72 | $312.99 |
| 2026-09-10 | $302.93 | $316.40 |
| 2026-09-11 | $304.06 | $325.33 |
| 2026-09-12 | $305.25 | $324.76 |
| 2026-09-13 | $299.17 | $318.92 |
| 2026-09-14 | $303.39 | $325.93 |
| 2026-09-15 | $295.75 | $313.07 |
| 2026-09-16 | $298.20 | $326.93 |
| 2026-09-17 | $294.90 | $321.89 |
| 2026-09-18 | $292.68 | $319.30 |
| 2026-09-19 | $293.53 | $303.07 |
| 2026-09-20 | $294.40 | $302.76 |
| 2026-09-21 | $298.07 | $306.87 |
| 2026-09-22 | $302.80 | $292.42 |
| 2026-09-23 | $291.77 | $282.85 |
| 2026-09-24 | $290.43 | $287.00 |
| 2026-09-25 | $290.09 | $286.30 |
| 2026-09-26 | $290.02 | $286.84 |
| 2026-09-27 | $288.65 | $283.86 |
| 2026-09-28 | $292.55 | $287.07 |
| 2026-09-29 | $294.34 | $291.75 |
| 2026-09-30 | $286.24 | $282.93 |
| 2026-10-01 | $279.64 | $275.93 |
| 2026-10-02 | $282.67 | $274.03 |
| 2026-10-03 | $284.58 | $276.13 |
| 2026-10-04 | $281.63 | $271.81 |
| 2026-10-05 | $286.38 | $269.90 |
| 2026-10-06 | $297.99 | $282.15 |
Discuss this study
Send the inputs and results to your own chat. Transaction ledger entries are excluded.
What the assistant receives
Only the text below, its numbers and links are shared. This does not grant access to your screen, account or ledger. For Gemini, Claude, Grok and long prompts, paste the copied text into the chat that opens.
Connect with MCP
Connect your assistant
Choose a client. All calculations use the same HTTPS endpoint; setup depends on the application.
Codex
Run these commands in your installed CLI client. They add the remote MCP server; this page does not execute commands on your computer. Public tools need no token or model API key from DCA Finance.
codex mcp add dcaFinance --url https://dca-finance.com/mcp
codex mcp listAfter connecting, ask the assistant to call get_methodology. To discuss your budget, provide the copied context; the server does not gain access to your ledger or account.
Every window: value, return and valuation date
The table includes every eligible starting date. Displayed amounts round to cents and percentages to two decimals. Downloads retain full calculation precision; results are compared before rounding.
Scroll the table horizontally to see every column.
| Start, UTC | Valuation, UTC | DCA value | Lump-sum value | DCA return | Lump-sum return | DCA minus lump sum, USD | Higher value |
|---|---|---|---|---|---|---|---|
| Sep 5, 2026 | 2026-10-04 23:00:00 UTC | $320.32 | $325.40 | +6.77% | +8.47% | -$5.08 | Lump sum |
| Sep 6, 2026 | 2026-10-05 23:00:00 UTC | $317.62 | $322.91 | +5.87% | +7.64% | -$5.29 | Lump sum |
| Sep 7, 2026 | 2026-10-06 23:00:00 UTC | $315.43 | $319.42 | +5.14% | +6.47% | -$3.98 | Lump sum |
| Sep 8, 2026 | 2026-10-07 23:00:00 UTC | $306.20 | $315.56 | +2.07% | +5.19% | -$9.36 | Lump sum |
| Sep 9, 2026 | 2026-10-08 23:00:00 UTC | $300.72 | $312.99 | +0.24% | +4.33% | -$12.27 | Lump sum |
| Sep 10, 2026 | 2026-10-09 23:00:00 UTC | $302.93 | $316.40 | +0.98% | +5.47% | -$13.47 | Lump sum |
| Sep 11, 2026 | 2026-10-10 23:00:00 UTC | $304.06 | $325.33 | +1.35% | +8.44% | -$21.28 | Lump sum |
| Sep 12, 2026 | 2026-10-11 23:00:00 UTC | $305.25 | $324.76 | +1.75% | +8.25% | -$19.51 | Lump sum |
| Sep 13, 2026 | 2026-10-12 23:00:00 UTC | $299.17 | $318.92 | -0.28% | +6.31% | -$19.75 | Lump sum |
| Sep 14, 2026 | 2026-10-13 23:00:00 UTC | $303.39 | $325.93 | +1.13% | +8.64% | -$22.54 | Lump sum |
| Sep 15, 2026 | 2026-10-14 23:00:00 UTC | $295.75 | $313.07 | -1.42% | +4.36% | -$17.32 | Lump sum |
| Sep 16, 2026 | 2026-10-15 23:00:00 UTC | $298.20 | $326.93 | -0.6% | +8.98% | -$28.73 | Lump sum |
| Sep 17, 2026 | 2026-10-16 23:00:00 UTC | $294.90 | $321.89 | -1.7% | +7.3% | -$26.99 | Lump sum |
| Sep 18, 2026 | 2026-10-17 23:00:00 UTC | $292.68 | $319.30 | -2.44% | +6.43% | -$26.61 | Lump sum |
| Sep 19, 2026 | 2026-10-18 23:00:00 UTC | $293.53 | $303.07 | -2.16% | +1.02% | -$9.55 | Lump sum |
| Sep 20, 2026 | 2026-10-19 23:00:00 UTC | $294.40 | $302.76 | -1.87% | +0.92% | -$8.36 | Lump sum |
| Sep 21, 2026 | 2026-10-20 23:00:00 UTC | $298.07 | $306.87 | -0.64% | +2.29% | -$8.80 | Lump sum |
| Sep 22, 2026 | 2026-10-21 23:00:00 UTC | $302.80 | $292.42 | +0.93% | -2.53% | $10.38 | DCA |
| Sep 23, 2026 | 2026-10-22 23:00:00 UTC | $291.77 | $282.85 | -2.74% | -5.72% | $8.92 | DCA |
| Sep 24, 2026 | 2026-10-23 23:00:00 UTC | $290.43 | $287.00 | -3.19% | -4.33% | $3.43 | DCA |
| Sep 25, 2026 | 2026-10-24 23:00:00 UTC | $290.09 | $286.30 | -3.3% | -4.57% | $3.79 | DCA |
| Sep 26, 2026 | 2026-10-25 23:00:00 UTC | $290.02 | $286.84 | -3.33% | -4.39% | $3.18 | DCA |
| Sep 27, 2026 | 2026-10-26 23:00:00 UTC | $288.65 | $283.86 | -3.78% | -5.38% | $4.79 | DCA |
| Sep 28, 2026 | 2026-10-27 23:00:00 UTC | $292.55 | $287.07 | -2.48% | -4.31% | $5.48 | DCA |
| Sep 29, 2026 | 2026-10-28 23:00:00 UTC | $294.34 | $291.75 | -1.89% | -2.75% | $2.59 | DCA |
| Sep 30, 2026 | 2026-10-29 23:00:00 UTC | $286.24 | $282.93 | -4.59% | -5.69% | $3.31 | DCA |
| Oct 1, 2026 | 2026-10-30 23:00:00 UTC | $279.64 | $275.93 | -6.79% | -8.02% | $3.70 | DCA |
| Oct 2, 2026 | 2026-10-31 23:00:00 UTC | $282.67 | $274.03 | -5.78% | -8.66% | $8.64 | DCA |
| Oct 3, 2026 | 2026-11-01 23:00:00 UTC | $284.58 | $276.13 | -5.14% | -7.96% | $8.45 | DCA |
| Oct 4, 2026 | 2026-11-02 23:00:00 UTC | $281.63 | $271.81 | -6.12% | -9.4% | $9.82 | DCA |
| Oct 5, 2026 | 2026-11-03 23:00:00 UTC | $286.38 | $269.90 | -4.54% | -10.03% | $16.48 | DCA |
| Oct 6, 2026 | 2026-11-04 23:00:00 UTC | $297.99 | $282.15 | -0.67% | -5.95% | $15.83 | DCA |
Calculation rules and data provenance
- Take 30 consecutive UTC days. The start advances by one day; the last eligible starting date is Oct 6, 2026.
- Buy $10.00 at 00:00 UTC each day using that hourly observation. Units are the sum of contribution / price. Lump sum uses the entire $300.00 budget at the starting observation.
- Both positions are valued at the same 23:00 UTC observation on the last day. The requested window ends at 23:59:59.999; this is not an additional available price. Final value is a valuation, not realized sale proceeds.
- Buy and sale fees, spread, slippage, taxes, conversion and interest on waiting cash are excluded. An hourly observation does not guarantee execution at that price. Differences no greater than USD 0.00000001 count as ties.
Source: CoinGecko, 1464 hourly observations across 61 UTC days. This uses the same saved snapshot, without a new history download or a new raw-price export. Provider source page.
- Method
dca-overlapping-30-day-windows-1- Source snapshot ID
cdebe296efb8e1d1bbec929695b5b8ff5871ad992c58f9ac66d69d4bc806c1e0- Price-series SHA-256
90baf9dc5dcc55a95de443a92fc0ba63dd6ed9beb4022e377953e4d86b1fff63- Report edition SHA-256
b1e465ba0c4fded71da4d12084b62cb90b27882b438a4b622046d8234e1ce9ca- Snapshot verified by server
- 2026-11-05 15:08:06.569Z
Methodology and model limits · Original backtest over the full snapshot period
The source backtest shows daily purchases over the entire saved period. It is not a separate selector for a window in this table. Reproduce windows using the rules, source identifiers and aggregate report downloads.
Download or cite the calculations
CSV contains every window’s aggregate result; JSON includes the same results, assumptions and provenance. These are calculated aggregates, not a new raw-price dataset. The link and fingerprints identify this edition.
Historical results and your plan answer different questions
This report shows how a short comparison depends on its starting date. The dashboard plans contributions around income, expenses and reserves; the ledger separates plans from executed trades. Paycheck-funded contributions that are not available at the start require a different funding assumption.
Open the free dashboard