What a backtest can and cannot tell you
How to read the numbers above, and what they don't settle.
Why average cost is the number that matters
Every unit you bought has a price attached, and average cost is the weighted average of all of them. It is the single number that decides whether the position is a paper gain or a paper loss: above current price, you are down; below it, you are up. Nothing else about the plan matters as much.
This is also why DCA does not eliminate risk, it just changes its shape. You still hold the asset, and the asset can still fall below what you paid for it on average — DCA only means you did not pay the single worst price available over the window.
Compound mode, in advanced settings, works differently: it takes profit at a set threshold and redeploys it rather than adding new principal, so it changes average cost through a separate mechanism from the recurring buys.
DCA against lump sum
The comparison table above runs both strategies on the exact same total capital and the exact same historical prices. Lump sum wins more often than not in an asset that trends upward over the test window, because it spends more time holding the full position while the price rises.
DCA wins when price falls after the start date and only recovers later, because spreading the buys out means some of the capital gets in at the lower prices along the way instead of missing them entirely.
The window problem
Every figure on this page is conditional on the start and end date you picked. Move the window by a few months and the winner between DCA and lump sum can flip, sometimes by a wide margin.
The honest way to use this tool is to run more than one period — 6 months, 1 year, 2 years — and look at whether the conclusion holds up across all of them or only in the one you happened to pick first.
None of this predicts what happens next. A backtest describes one path the market already took, not a path it will take again.