Which wins, lump sum or DCA, for any given stretch of Bitcoin's history? That's not actually a debate — it's a number you can compute directly from real price data once a start date, an amount, and a comparison schedule are fixed. This site's calculator does exactly that, and the answer flips entirely depending on which window gets tested.
Why this debate has a computable answer, not just an opinion
Whether lump-sum or DCA "wins" for a specific historical window isn't a matter of theory — it's directly computable from real price data once you fix a start date, an amount, and a comparison DCA schedule. This site's Lump Sum Calculator does exactly that: pick a historical date and dollar amount, and see precisely what that single purchase would be worth as of today's price, using real historical data rather than a stylized example.
The general pattern (and why it's not a rule)
Mathematically, a lump sum invested on day one gets full exposure to the entire subsequent price move immediately, while a DCA plan only gradually gains exposure as contributions are made over time. That means lump sum tends to outperform whenever the asset trends upward over the period studied (since more capital was exposed to the gain, earlier), and tends to underperform whenever the asset falls significantly right after the lump-sum date (since DCA would have kept buying at progressively lower, more favorable prices). Neither outcome is guaranteed in advance — it depends entirely on the specific price path that actually happened.
Why cherry-picked examples mislead
A single commonly-cited "lump sum beat DCA" or "DCA beat lump sum" example usually picks a particular start date that makes the intended point. Because Bitcoin's price history includes both multi-year uptrends and multi-year drawdowns, either conclusion can be "proven" by choosing the right window. This site's calculators let you test the specific dates relevant to your own situation rather than trusting someone else's cherry-picked comparison.