What an equity curve is
An equity curve is a chart of your trading account's total value over time — the account balance plus the floating profit or loss of every position that is still open. It is the line a serious trader looks at first, because it answers the only question that matters: how much was my account actually worth at every moment, including the trades that were underwater?
Most vendor marketing shows you a balance line instead. The balance only changes when a trade closes. Between closes it sits flat, no matter how deep the open positions have sunk. That is why a grid or martingale EA can advertise a beautifully smooth, rising chart while quietly holding a basket of losing trades that never appears on the balance line — until the day it is force-closed and the account gaps down.
Balance line vs equity curve: the tell
Put the two lines on the same chart and read the gap between them:
- Lines hug each other. Trades close near where they open; little floating risk. This is what a defined-risk EA with a stop-loss on every position looks like.
- Balance climbs, equity dips repeatedly below it. The EA is holding losers and closing winners. Each dip is a basket of open trades underwater. The depth of the biggest dip is your real maximum drawdown — often far larger than any number in the vendor's stats.
- A sudden vertical drop in equity that snaps back up. A grid that averaged down and recovered. It recovered this time. The move that does not come back is the one that wipes the account.
This is the mechanism behind the warnings in our grid and martingale risk guide: the balance line is the story the EA tells; the equity curve is what actually happened.
The metrics you read off the curve
| Metric | What it tells you | Where to look |
|---|---|---|
| Maximum equity drawdown | The worst peak-to-trough drop including open trades — your true risk | Deepest point below the running high |
| Recovery time | How long the curve stayed underwater | Width of the drawdown valleys |
| Slope consistency | Whether gains are steady or lumpy | Smoothness of the rising sections |
| Balance/equity gap | Hidden floating risk | Vertical distance between the two lines |
The full set of numbers — profit factor, Sharpe, monthly return — is covered in our trading metrics guide. But the equity curve comes first, because a single glance at its shape tells you whether those numbers are trustworthy or cosmetic.
Why the curve matters more for EAs than for manual traders
A manual trader feels the drawdown and can step in. An Expert Advisor does not: it keeps trading its rules through the worst of it. So the equity curve is not just a report card — it is a forecast of the pain you will have to sit through without touching the account. An EA whose historical equity curve dropped 40 % underwater will do it again; the only question is whether your account and your nerves survive it. That is exactly why prop firms measure equity, not balance, for their drawdown rules — more on that in what is a prop firm.
How to see your own combined equity curve
One EA's curve is only half the picture. If you run a portfolio, what matters is the combined equity curve across every account and broker — because two EAs can each look fine while their drawdowns line up on the same bad week and stack into one deep hole. Reading that requires pulling equity, not balance, from all accounts at once.
Our free EA portfolio tracker does exactly that: connect any number of MT4/MT5 accounts and it draws the combined equity curve, so you see the real portfolio drawdown instead of a set of flattering individual balance lines. How to combine EAs without stacking correlated risk is covered in the EA portfolio management guide; how to size each one is in position sizing and risk per trade.