Trade Copier

What a trade copier does

You trade, or a bot trades, on the source account. The copier sees each new order, each change to a stop or target, and each close. It sends the same instruction to every destination. Some copiers run inside the platform on the same computer. Others run on a server and talk to each account over the internet.

People use copiers to run one strategy on several accounts, to spread one idea across accounts held with different providers, or to keep a live account matched to a test account. A copier is not the same as a service that lets strangers follow a leader. For that, see copy trading. Here all the accounts are yours, so you control both ends and carry all the risk.

Latency: the copy is always late

Latency is the time between the source order and the destination order. It has parts: the copier noticing the trade, the message travelling, the destination accepting it, and the fill. It is usually small, and in a quiet market the price barely moves in that time. In a fast market it can move several pips, and the destination gets a worse price than the source. A copier on a computer far from the trading server, or on a weak connection, adds more. See forex VPS.

A strategy that earns only a few pips per trade can be wrecked by latency alone, so the copier is part of the strategy, not a neutral pipe. See slippage.

Lot scaling

The destination is rarely the same size as the source, so the copier scales. The common modes are a fixed lot, a multiple of the source lot, and a ratio of balances or equity. A ratio keeps the risk per trade as a similar percent of each account. A fixed lot does not.

Then the size must fit the destination's rules. Each account has a smallest lot, a lot step and a largest lot, and these vary by provider. Check yours on the account itself. If the scaled size falls between steps, the copier either rounds down, rounds up or skips. All three change your risk. If a stop is also scaled, a rounded size changes the dollar risk on that trade. See the lot size calculator.

Worked example: scaling five trades

Everything here is made up. The source account holds $10,000 and the destination holds $2,500, so the ratio is 0.25. The destination's lot step is 0.01 and the copier rounds down. Each row is a different source trade. A lot is worth $10 a pip in this example.

Calculated by us on 29 Oct 2026, exact. The largest trade copies cleanly. The 0.30 lot trade wanted 0.075 and placed 0.07, 7% short. The 0.10 lot trade wanted 0.025 and placed 0.02, 20% short. The 0.05 lot trade placed 0.01 against 0.0125, 20% short. The 0.03 lot trade wanted 0.0075, rounded to 0.00 and was not placed at all. If that skipped trade was a winner, the destination missed it. If it was a hedge or a recovery step for a larger position, the destination is now carrying risk the source does not. A bot that adds small positions, such as a grid or a martingale ladder, has this problem on every step.

Now the delay. The next table uses one 0.25 lot copy and made-up price drift while the order travels.

Calculated by us on 29 Oct 2026, exact for these made-up drifts. A quiet-market copy costs $0.25 extra. The same order placed 900 ms late during a fast move costs $15.00, 60 times as much. The drift is an assumption, not a measurement of any system, so measure your own.

How copiers fail

• The program stops. The computer sleeps, restarts or loses the connection. The source keeps trading and the destinations do nothing.
• A close is missed. The open arrived and the close did not, so a destination holds a position the source has already left.
• An order is rejected. Not enough margin, a closed market, a size outside the limits or a price that moved too far. Some copiers retry and some drop it. See requotes.
• Different contract details. Symbol names, contract sizes, swaps and trading hours differ between accounts. The copy can be the right size on paper and the wrong exposure in practice.
• Duplicates. A restart that re-reads open trades can copy them a second time.
• A margin call on a smaller account. A destination with less room can be stopped out while the source survives. See margin call.

How to check a copier before any money

• Run it on demo accounts on both sides and export both trade lists. Match them line by line: count, size, open time, close time, price.
• Force the failures: stop the program with positions open, cut the connection, change a stop, send a size below the minimum.
• Measure the delay in quiet and busy periods, not the average.
• Write down what happens to a trade the destination cannot place, and decide that in advance.
• Add a check that compares open positions on both sides and tells you when they differ. See paper trading.

What this page does not tell you

It does not describe any particular copier, and the delays and rounding rules here are made up or vary by provider. It does not say a copier is a good idea for a given strategy. It says a copy is a second order with its own price, size and failure risk.