Grid, martingale and averaging expert advisors are among the most sold robots for gold and forex. Their backtests often show a straight, rising balance line that is very hard to ignore. That line is real, but it hides where the risk sits. This guide explains the mechanism and the numbers to check.
How a basket system earns
A typical basket EA opens a position, and if price moves against it, opens more positions at set distances, sometimes with larger lots. When price retraces even part of the way, the whole basket is closed at a small combined profit. In ranging markets, which are most of the time, this harvests mean reversion again and again. That is why the win rate is high and the curve is smooth.
Where the risk hides
- Balance versus equity: the balance only updates when baskets close, so floating losses do not appear on the balance line. Always look at the equity curve.
- Exposure grows non-linearly: each added level increases total lots. With a lot multiplier, exposure grows geometrically, so the last few levels carry most of the risk.
- The tail event: the system fails in a strong, one-directional move without a retrace, such as a major news shock or a trend day on gold. One failed basket can cost more than many months of closed profits.
The numbers that matter
| Metric | Why it matters |
|---|---|
| Maximum equity drawdown | The real worst moment, including floating losses |
| Deepest basket (levels opened) | How close the system came to its limit |
| Largest single basket loss | Compare it to average monthly profit |
| Distance price must travel to stop out | Converts risk into points you can compare with gold's daily range |
| Results at doubled spread | Small-target baskets are very spread-sensitive |
Protections worth building in
- Hard equity stop: closes everything at a fixed percentage drawdown. It turns an unknown worst case into a known one.
- Maximum levels and maximum total lots: caps how big a basket can grow.
- Time and news filters: no new baskets before high-impact releases or into the daily rollover spread.
- Trend filter or hedge logic: pauses adding against a strong move, or opens a defined hedge, accepting a smaller loss to avoid a full stop-out.
- Auto-reset after a hit: a cooling-off rule so the EA does not immediately restart into the same move.
A fair way to judge one
Divide the largest basket loss, or the equity-stop amount, by the average monthly profit. The answer is roughly how many months of gains one bad day can erase. If you would not accept that trade-off, no backtest curve should change your mind.
Grid and martingale systems are high-risk by design. Equity stops and filters reduce the damage of a bad event but cannot remove it. See our Risk Disclosure.