A master account on MT4 opens 0.37 lots of EURUSD. A follower on cTrader receives it as 37,000 units. A second follower on MT5 receives 0.37 lots, but the account is in netting mode and already holds a short, so the copy nets down instead of opening a second position. Three accounts, one signal, three different outcomes. None of the software failed. The platforms simply do not model a position the same way.
The four translations a cross-platform copier has to do
Symbol names come first. EURUSD on one server is EURUSD.m or EURUSD.pro on another, gold is XAUUSD or GOLD, and index CFDs are named almost arbitrarily. Every copier has an alias table, and it is the first thing to inspect. An unmapped symbol should refuse to copy and log the reason, never fall through to a nearest match.
Contract size comes second. MT4 and MT5 express volume in lots against a contract size defined per symbol. cTrader expresses volume in units of the base currency. The conversion is arithmetic, but the arithmetic depends on the destination broker's contract specification, not the source's. If a broker runs a 10,000 unit mini contract where the master runs 100,000, a copier that copies the lot number rather than the notional gives you a tenth of the intended exposure.
Rounding comes third, and it bites small accounts. If the destination has a minimum volume of 0.01 lots and a step of 0.01, a calculated 0.004 has to become either 0.01 or nothing. Rounding up quietly multiplies risk on a small follower account. Rounding down to zero silently drops the trade. Pick one deliberately and know which trades it will affect.
Position model comes fourth. MT4 is hedging only. MT5 accounts can be hedging or netting depending on how the broker configured them. cTrader nets by default per symbol. A strategy that opens opposing positions in the same instrument, or scales into a position with separate tickets, does not survive the trip to a netting account intact. If the master runs a grid or any structure with multiple simultaneous tickets, the copy is a different strategy. The MT4 and MT5 differences matter here more than anywhere else.
Where the latency comes from
Inside a single platform, a copier reads the master terminal's trade events and sends orders through the same API. Across platforms you add hops: the source terminal or its API, a relay service, the destination platform's API, then the destination broker's server. Each hop has a queue.
The realistic budget is tens to hundreds of milliseconds when everything is colocated sensibly, and considerably worse when the relay lives on a laptop in another country. That is fine for a swing strategy holding for days. It is fatal for a scalper working two-pip targets, because by the time the copy lands the price that justified the entry is gone. A VPS near the broker's servers is the cheapest improvement available, and the slippage that remains is a real cost you should measure rather than assume.
Cross-platform copying changes the strategy, it does not just relocate it. Before connecting real money, run the copy on a demo alongside the master for long enough to compare fills trade by trade. Leveraged trading carries a high risk of loss and a copier does not reduce it.
Instrument coverage and the trades that never arrive
Not every destination broker offers every instrument the master trades. Exotic pairs, single-stock CFDs, and specific index contracts frequently do not exist on the follower's server. The copier has to decide what to do with a signal it cannot execute, and there are only two defensible answers: skip and log, or halt and alert. Substituting a correlated instrument is a decision no copier should make on your behalf.
Trading hours differ too. A master on a broker with extended index hours can open a position when the follower's server has that symbol closed. The copy is rejected, the master is in the market, the follower is not, and unless the copier reconciles positions when the session opens the two accounts stay out of step for the rest of the trade.
Stops, targets and partial closes
Attached stop loss and take profit levels usually copy cleanly because they are price levels, and price on the same instrument at two brokers differs only by the markup. That difference is not zero. A broker running a wider spread will trigger a stop placed at an identical price at a slightly different moment, and on tight stops the effect is visible.
Modifications are the harder part. Moving a stop, closing half a position, closing everything at market: each is a separate instruction the copier has to map back to the right destination ticket. Partial closes on a netting platform are a volume reduction rather than a ticket close, so the copier needs its own record of which portion belongs to which master ticket. Ask any vendor how partial closes are handled and treat a vague answer as a no. Our overview of how copiers work generally covers the single-platform case.
When to stop copying and start integrating
A copier is glue. It is the right tool when the accounts genuinely live on different platforms for reasons you do not control: a prop firm on one stack, a personal account somewhere else, followers who each chose their own broker. It is the wrong tool when a firm is running multiple platforms internally and copying between them to paper over the split. At that point every reconciliation problem in this article becomes an operational cost you pay every day, and consolidating onto one stack is cheaper. Firms in that position usually end up looking at what a single platform across the whole client base would remove from the ops load.
Whichever route you take, instrument the thing. Log every signal received, every order sent, the latency between them, the requested volume, the filled volume and the rejection reason where there is one. Without that record you cannot tell a copier problem from a broker problem, and you will spend weeks arguing about which it was. Slippage tracking and the cTrader side of the equation both help.
"Same symbol, same direction, different platform, and the position sizes come out different. That is not a bug, that is two contract specifications disagreeing."
— Alex Onta, Executive Director, SINGUARD
Key Takeaways
- Symbol names, contract sizes, volume rounding and the hedging or netting model all have to be translated per destination.
- A netting destination cannot reproduce a strategy that holds multiple opposing tickets in one instrument.
- Each additional hop adds latency, which is tolerable for swing strategies and fatal for scalping.
- Missing instruments and mismatched trading hours leave accounts out of step unless the copier reconciles.
Frequently Asked Questions
Can I copy from MT4 to cTrader?
Yes, with a copier that converts lots to base-currency units using the destination broker's contract specification and maps symbol names. The conversion has to use the destination's spec, not the source's, or the exposure will be wrong.
Why is my copied position size different from the master?
Usually contract size or rounding. The destination broker may define a different contract size for the same symbol, and any calculated volume below the minimum step has to be rounded up or dropped, which changes the exposure either way.
How much latency does a cross-platform copier add?
It depends entirely on where the relay runs. Tens to hundreds of milliseconds is realistic with the components hosted near the brokers, and much worse when the bridge runs on a home connection. Measure it on your own setup rather than trusting a vendor figure.
About the Author
Alex Onta is an Executive Director at SINGUARD. He built eTrader, the terminal, the mobile apps, eTrader Broker, Copytrading, Business and Community, along with the worldwide clustered-server infrastructure it all runs on, with his brother Roman Onta helping on the design, and he leads that division today. Together with Roman he builds the Prop Firm CRM, the Broker CRM, Scalegram and CopySignals, and the two of them carry worldwide compliance, payment processing and international business structuring side by side. He lives and works in Dubai for most of the year. Meet the executive duo leading Singuard's five divisions.