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Before any bot runs, work out the lot that risks only the share of the account you chose, from your own stop distance.
What is included
- What it is, in plain words
- The formula or mechanism, with exact arithmetic
- How it hits grid, martingale and DCA bots
- A check you can run before you switch a bot on
Who it is for
- People who run or plan to run a trading bot
- Anyone reading a backtest or a bot sales page
- Readers who want the numbers, not the pitch
- Not advice, and not a signal service
Key facts
- A forex trading bot is software that watches currency prices and places, moves and closes orders by rules you or someone else wrote. The most common kind on retail platforms is the forex EA.
- A bot differs from a signal service. A bot sends orders itself. A signal service tells a person what to trade, and the person still has to act. A trade copier sits between the two.
- To run, a bot needs a trading account, a platform it can attach to, a steady connection and a machine that stays on. A rented server is one option, covered under forex VPS.
- Running cost is a fixed drag. In the made-up example here a $25 a month server is 5.00 percent of a $500 account every month and 0.50 percent of a $5,000 one (calculated by us on 29 Oct 2026, exact).
- Bots fail through costs, tuning to old data, ladders that grow losses, rule changes by the broker and the machine or connection going off.
What a forex trading bot is
Forex is the market where one currency is traded for another. A forex trading bot is a program that does the clicking for you. It reads prices, applies rules such as "buy when the fast average crosses the slow one", checks its limits, and sends an order to your broker. It repeats this every bar or every tick, all day, without getting tired or changing its mind.
That is both its use and its limit. It follows the rules exactly, including the bad rules, and it follows them when you are asleep. A bot is not an opinion about where the price will go. It is a rule set with a body attached.
Bot, EA and signal service: the differences
The three terms get mixed up. They are different things, and the difference matters for what you have to do and what can go wrong.
- Forex trading bot. The general word. Any program that places forex orders by rule. It can be a script that talks to a broker through its programming interface, or a program on a trading platform.
- EA (expert advisor). A bot written for a particular trading platform, which runs inside it on a chart. The expert advisor page explains the idea. All EAs are bots, but not all bots are EAs.
- Signal service. A person or a program that sends alerts: "buy this pair here". A human decides whether to act. Nothing is traded unless you place the order. It is not a bot by itself, though a service can be wired to one.
- Trade copier. A tool that repeats trades from one account onto another. Any fault or delay in the first account carries over to the copies.
The practical difference is control. A bot trades on its own, so the thing you must control is its risk before it starts. A signal service leaves the risk with you on every order.
What a forex bot needs to run
- An account. Learn on a demo account first. Demo prices and fills are not the same as live, and the page says how they differ.
- A platform or interface. Most retail bots run on MT4 or MT5 as EAs. The MT4 vs MT5 page compares them. Others call a broker's interface from a script.
- A steady machine and connection. The bot only works while the platform is open and online. A laptop that sleeps leaves open trades unmanaged. A hosted server stays on, at a monthly price.
- Rules for size and loss. The lot size, the stop and the daily loss limit. The bot cannot choose these for you. The lot size calculator turns a stop into a lot.
- Time to watch it. You read its log, check its trades against its rules and notice when the market has changed.
Worked example: what it costs just to keep a bot running
Before a bot makes anything, it has to pay for the thing it runs on. This is a made-up server at $25 a month, $300 a year. The cost is the same whatever the bot does. Against a small account it is a large slice, and it comes on top of spread and commission.
| Account | Server cost a month | Percent of account a month | Cost a year |
|---|---|---|---|
| $500 | $25 | 5.00% | $300 |
| $1,000 | $25 | 2.50% | $300 |
| $2,000 | $25 | 1.25% | $300 |
| $5,000 | $25 | 0.50% | $300 |
On $500 the server takes 5.00 percent every month, so the bot must earn that before it is ahead. On $5,000 the same server takes 0.50 percent. Calculated by us on 29 Oct 2026, exact. All figures are made up and server prices vary. A bot that trades rarely carries the same fixed cost on fewer trades, as the figure below shows. If your own computer can stay on and online, you may not need a server at all. That is a choice, with a trade-off in reliability.
How a forex trading bot fails
- Costs. Spread, commission, swap and the cost of the machine are paid on every day and every trade. A thin edge disappears. See spread.
- Tuning to the past. Rules adjusted until old data looks good fail on new data. That is overfitting.
- Ladders and doubling. A bot that adds to losers wins often and loses rarely and large. See martingale and margin call.
- Different fills. The price the bot saw is not always the price it gets. Fast markets widen this gap. See slippage.
- Changed rules or conditions. Brokers change spreads, leverage and execution rules, and markets change from trending to ranging. A bot does not notice unless it was written to.
- The machine or connection goes off. Open trades are left alone. Stops held on the broker's server are safer than stops the bot would have to send.
- A bad product. A bot sold with a promise of income, or with a test that shows no costs, is a warning. See best EA for MT4 for a checklist that works on any bot.
What this page does not tell you
It does not say a forex bot is a good or bad idea, or that any bot makes money. The server price and account sizes are made up, and your costs and rules will differ. Check your broker's terms on automated trading before you run one.
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FAQ
Frequently Asked Questions
What is a forex trading bot?
It is a program that places currency trades by fixed rules. It reads prices, checks its limits and sends orders to a broker without you clicking each one.
Is a forex trading bot the same as an EA?
An EA is one kind of forex bot, written for a trading platform and run on a chart there. Other bots are scripts that talk to a broker directly.
How is a bot different from a signal service?
A bot sends the orders itself. A signal service only tells a person what to trade, and the person has to act. A trade copier repeats trades from one account to another.
Do I need a server to run a bot?
Only if your own computer cannot stay on and online. The bot only works while its platform is running, so a machine that sleeps or loses connection leaves trades unmanaged.
Can I test a bot without risking money?
You can use past data and a demo account. Both differ from live trading, in fills, costs and your own reactions, so treat their results with care.
Are the numbers on this page real?
Example numbers are made up to show how the maths works, and the page says so. A figure only counts as exact when the page says it was calculated on a stated date. Nothing you enter in a calculator leaves your browser.
Can I use this to decide whether to run a bot?
It can show whether a bot's numbers hold together and how much an account can lose. It cannot say what the market will do, and it is not advice. Use it to ask better questions, then read the terms of your own broker or exchange.
Is this financial advice?
No. It is general education. The numbers are made up and your costs, broker and rules will differ.
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