DCA ladder
Each cycle opens with a base market buy. Two kinds of limit orders are posted immediately after it fills: a take-profit sell at the volume-weighted cost basis plus tp_pct, and a ladder of safety buys below entry. The k-th safety order sits at a cumulative deviation of deviation_pct · (1 + step_scale + … + step_scale^(k−1)) below entry — with the shipped values, 3.00%, 7.20%, 13.08% — sized at safety_usd · volume_scale^(k−1). Every filled safety order re-anchors the take-profit on the new cost basis; a filled take-profit closes the cycle and the next bar starts a new one.
Capital at risk
Maximum ladder exposure is base_usd + safety_usd · Σ volume_scale^(k−1). The backtest config's $30 base and $30 first safety order put $172.50 of ladder against $165 of cash; the live config halves both to $15, for $86.25 against a $125 live allocation. When a configured ladder exceeds its allocation the loader warns and lets it run — the risk gate and the cash on hand clip at order time, by decision, rather than silently resizing the ladder.
| Parameter | Default | Meaning |
|---|---|---|
| base_usd | 30 (live 15) | Base order size opening each cycle. |
| safety_usd | 30 (live 15) | First safety order size; later ones scale up. |
| max_safety | 3 | Ladder depth. |
| deviation_pct | 3.0 | First safety-order deviation below entry. |
| step_scale | 1.4 | Each further deviation widens by this factor. |
| volume_scale | 1.5 | Each further safety order grows by this factor. |
| tp_pct | 2.5 | Take-profit above the volume-weighted cost basis. |
Known failure modes
A sustained downtrend exhausts the ladder and leaves inventory below cost with no take-profit in reach. The win-rate illusion is structural: every closed cycle is a win by construction, so DCA can print 100% win rate on a negative return — which is exactly why every win-rate figure on this site carries its definition.