Equity Curve Rules: Trading Smaller While the Curve Is Falling

[Shadow Trader]

Equity curve trading applies a simple idea: size follows recent performance. When the account curve sits below its own moving average, or below a recent peak by a stated margin, risk per trade is cut. When the curve recovers, normal size returns.

The logic is defensive. Strategies sometimes stop working because the market regime changed, and a falling curve may be the first visible sign. Reducing size limits the damage while the cause is investigated, without forcing a decision to abandon the method altogether.

The rule has costs worth stating plainly. If losses are ordinary variance rather than a broken edge, trading smaller during the dip means recovering more slowly, since the best trades after a losing run are sized down. Whipsaw is the other risk: a curve that oscillates around its average will trigger size changes repeatedly, each one adding small distortions.

A cleaner design uses few parameters. For instance, a single drawdown band from the latest equity high triggers a fixed reduction, such as halving risk, and a defined recovery condition restores it. Fewer parameters leave less room for overfitting the rule to past data. Testing the rule on historical trade logs, including a deliberately unlucky ordering of trades, shows whether it helps or merely feels prudent.

[FXS HongKong Scalper]

We tried a simple version: half size when the equity curve is below its 20-trade moving average. Over a year of our records, it reduced the maximum drawdown by about a third, but the total return was lower too, because the strategy often recovered while size was reduced.

So it works more as a risk tool than a profit tool. If drawdowns are the main problem, for example in a prop account, it's worth it. For a personal account with a strategy that has a stable edge, the cost of lower returns can outweigh the benefit.