Trade Copier vs Expert Advisor (EA): What's the Difference?
An EA automates a strategy inside one MetaTrader terminal; a trade copier mirrors trades across accounts. They solve different problems — here's how they compare.
27 Jun 2026 · 4 min read
"Trade copier" and "Expert Advisor" get used almost interchangeably, but they're different tools that solve different problems. An Expert Advisor (EA) is an automated program that runs a strategy inside one MetaTrader terminal. A trade copier takes trades that already happened on one account and repeats them onto others. You can use either, both, or neither — it depends on what you're trying to do.
What an Expert Advisor (EA) is
An EA is a script written in MQL4/MQL5 that runs attached to a chart in MetaTrader. It watches the market and places, modifies or closes orders on that one account according to its rules — entries, exits, sizing, the lot. In other words, an EA decides and executes trades on its own. It only acts on the single terminal it's attached to, and it only runs while that terminal is open and the "algo trading" toggle is on.
What a trade copier is
A trade copier doesn't decide anything. It watches a source account and, whenever a position opens, changes or closes there, it repeats that same action onto one or more follower accounts. The decisions still come from wherever the source trades originate — you trading by hand, or an EA running on the source. The copier's job is purely to mirror, fast and faithfully, and to size each follower correctly. It's a distribution tool, not a strategy.
How they compare
| How they compare | Expert Advisor (EA) | Trade copier |
|---|---|---|
| What it does | Decides + places trades from a strategy | Repeats trades that already happened |
| Scope | One account / terminal | One source → many followers |
| Cross-broker | No — tied to its terminal | Yes — followers can be different brokers |
| Setup | Install the .ex4/.ex5, attach to a chart, enable algo | Connect accounts, set the copy rules |
| Sizing | Its own rules on its one account | Scales each follower (ratio / multiplier) |
| Needs the terminal open | Yes (unless on a VPS) | Local copiers yes; a cloud copier, no |
Note the table compares the categories. Plenty of copiers are themselves built as EAs (a "copier EA" you attach to both terminals) — that's an implementation detail. The useful distinction is the function: an EA generates trades; a copier distributes them.
Can you use both?
Yes — they compose. A common setup is an EA (or your own manual trading) generating trades on a source account, and a copier fanning those trades out to several follower accounts. The EA decides; the copier distributes. Neither replaces the other.
Where Trepeat fits
Trepeat is a cloud trade copier — the distribution half, not the strategy half. There's no EA to install and nothing to attach to a chart: you connect a MetaTrader account once and it repeats the trades you (or your own EA) take on it onto every follower you connect, sized automatically. It runs on managed infrastructure, so the source terminal doesn't have to stay open. It never decides a trade — it only repeats your own. If you want the strategy automated, that's an EA's job; if you want one account's trades mirrored across many, that's the copier's. See also cloud vs local (VPS) copiers and what a trade copier is.