Learn
AI Expert Advisors: What the AI Does and Why Your Backtest Can't Show It
At a glance
An AI expert advisor can make its decisions in three places: in fixed rules, in a trained model inside the EA, or in an AI service on the internet such as ChatGPT, Claude or the seller's server. Only the first two can be backtested. In our own Strategy Tester run on 31 October 2026, an EA that asked an online service sent 11 requests and got 11 refusals, error 4014, because MetaTrader blocks web requests in the tester. Of 38 MQL5 Market listings with AI in the name among the first 700, 21 used AI only as a word, 5 named an online AI service, and only 2 of those 5 said that their backtest leaves the AI out.
On this page
An Expert Advisor sold as “AI” can mean three very different things. It matters for one reason above all: the backtest the seller shows you, and the one you run yourself, may not contain the AI at all.
This guide explains where the AI in an EA can sit, shows what MetaTrader's Strategy Tester does with each kind, and reports what 38 AI-labelled listings on the MQL5 Market say about their own AI. Whether a particular EA makes money is a separate question; our Expert Advisor buying checklist covers it.
Disclosure and date: The tester run and the Market count are our own, from 31 October 2026. We name no third-party products and make no judgement on their profitability. RoboXpert sells its own Expert Advisors and a risk tool, so we have a commercial interest in this subject; none of our EAs uses AI in its trading decisions. AI assisted with research, coding and drafting. See our editorial methodology.
Where the AI sits in an AI expert advisor
The word AI on an EA says nothing about where the trading decision is made. There are three possibilities, and they differ in what you can check before you buy.
The table adds what each kind means for you as a buyer:
Scroll horizontally if needed
| Where the decision is made | What a backtest shows | What to ask |
|---|---|---|
| Fixed rules in the EA's code. Many “AI” EAs are this: rules someone wrote, perhaps with an AI tool's help | The same rules that run live | What are the rules, and how does exposure grow after a loss? |
| A trained model inside the EA, usually in the ONNX format, compiled into the file | The model, on historical data, as long as it is the same model version | Which model version produced the backtest, and how often is it retrained? |
| An AI service on the internet: ChatGPT, Claude, DeepSeek or the seller's own server, called with an API key | Not the AI. The EA gets no answer in the tester and runs whatever it does without one | What does the EA do when the service does not answer, and is there a live record with the service switched on? |
Our introduction to what an Expert Advisor is separates “built with AI” from AI in the trading decision. This guide is about the second.
Our test: an EA that asks an online AI in the Strategy Tester
To see what the tester does with the third kind, we wrote a small EA that does what an EA with an online AI does: it sends a web request, once a day, and waits for an answer. Instead of an AI service it asks a public page on our own website, because the point is whether any answer arrives at all. It never trades.
The request in the EA is one line of standard MQL5:
int code = WebRequest("GET", InpUrl, "", 5000, body, answer, headers);
We compiled it with 0 errors and 0 warnings and ran it in MetaTrader 5's Strategy Tester on a BlackBull Markets demo account, gold on H1, 1 to 15 October 2026. The tester's log, unchanged except that we shortened it to the relevant lines:
13:14:23.905 Startup MetaTester 5 build 6230, 25 Sep 2026
13:14:24.532 RX_WebAIProbe (XAUUSDp,H1) 2026.10.01 00:00:00 RXPROBE OnInit: tester=1 WebRequest code=-1 error=4014 bytes=0 after 0 ms
13:14:24.580 RX_WebAIProbe (XAUUSDp,H1) 2026.10.01 01:00:00 RXPROBE 2026.10.01: tester=1 WebRequest code=-1 error=4014 bytes=0 after 0 ms
13:14:24.582 RX_WebAIProbe (XAUUSDp,H1) 2026.10.02 01:00:00 RXPROBE 2026.10.02: tester=1 WebRequest code=-1 error=4014 bytes=0 after 0 ms
13:14:24.588 RX_WebAIProbe (XAUUSDp,H1) 2026.10.14 23:59:59 RXPROBE summary: calls=11 answered=0 failed=11 last_error=4014
All 11 requests failed immediately with error 4014, which the MQL5 reference lists as ERR_FUNCTION_NOT_ALLOWED, “Function is not allowed for call” (MQL5). That is by design. The WebRequest reference states that “WebRequest() cannot be executed in the Strategy Tester”, and that live, the address must first be added to the list of allowed URLs under Tools → Options → Expert Advisors.
So a backtest of an EA whose AI sits on a server shows one of two things: the EA's built-in fallback rules, or nothing. Neither is the AI. A free demo of such an EA on the MQL5 Market runs in the same tester, so it cannot show the AI either. The only evidence of the AI part is a record from a live or demo account with the service switched on.
What 38 AI expert advisors on the MQL5 Market say
To see how sellers describe their AI, we saved the first ten pages of the MQL5 Market's Expert Advisors for MetaTrader 5 in its default order: 700 listings out of 17,874 shown that day. 38 had AI wording in the name: “AI”, “neural”, “GPT” or a model name. We did not count names such as “Quantum”, which suggest technology without saying AI. We then read each of the 38 descriptions and coded by hand what it says about the AI.
The same counts as a table, with what each group lets you check:
Scroll horizontally if needed
| What the description says about the AI | Listings | What you can check from it |
|---|---|---|
| “AI” only as a word: no model type, no location | 21 | Nothing about the AI; judge it as a rule-based EA |
| A model type, such as neural network or machine learning, but not where it runs | 7 | Ask whether the model is inside the EA or online |
| A model inside the EA, in all five cases ONNX | 5 | The backtest runs the model; ask for the version |
| An online AI service with an API key or web requests | 5 | The backtest leaves the AI out; 2 of the 5 say so on the page |
A few more facts from the same 38 listings: 4 were free and the median price of the paid ones was $299. 14 linked a live MQL5 signal, which is the kind of record that can show an online AI at work. 29 had star ratings, 21 of them from fewer than ten reviews; what ratings tell you is in our guide to reading an MQL5 Market page.
A model inside the EA: testable, but which model?
An EA that carries its model inside the file is the one kind of AI EA a backtest can show. MQL5 supports trained models in the ONNX format and states that “models created for operations in the financial markets can be validated in the MetaTrader 5 terminal Strategy Tester” (MQL5). We did not run an ONNX model ourselves for this guide; that statement is MetaQuotes' own.
Two catches remain. A model trained on the same years it is then tested on will look good in that test, so ask which period the model was trained on and which period the backtest covers. And a model that is retrained every few months is a different EA after each retraining; a backtest is evidence only for the version it was run with.
The AI label and grid or recovery logic
6 of the 38 descriptions say the EA uses a grid, a martingale, zone recovery or larger orders after a loss to recover it. The AI in such an EA may decide where to start, but the risk comes from the position building, and that part is fixed rules a backtest shows well. Read the backtest for how far the account fell while positions were stacked, not for the AI. Our guide to grid trading and martingale shows what to look for.
Many of the other descriptions say the EA uses no grid or martingale. A statement in a description is not a test; a backtest shows quickly whether lot sizes grow after losses.
Questions to ask before you buy an AI EA
The seller knows where the AI sits. These questions get it out of them, and the answers decide which evidence you need.
- Where is the trading decision made? In the EA's rules, in a model inside the file, or by an online service? A seller who cannot say has told you something.
- For a model inside the EA: which version produced the backtest, which years was it trained on, and how often is it retrained?
- For an online service: which service, what does it cost, which address must be allowed in MetaTrader, and what does the EA do when the service is down or slow?
- What does the backtest contain? Fallback rules, the model, or nothing? Ask the seller to say it in writing if the page does not.
- Is there a live or demo record with the AI switched on, long enough to include losing weeks? For an online AI, that is the only evidence of the AI part.
The CFTC's advice applies to every answer: “AI technology can't predict the future or sudden market changes” (CFTC). If the offer asks you to deposit money with the seller rather than run software on your own account, read Is AI trading legit? first.
What we did not test
- We tested what happens to a web request in the Strategy Tester, not any third-party AI EA. We did not buy, rent or run one.
- We did not run an ONNX model; the statement that models run in the tester is from the MQL5 documentation.
- We did not test a live account with an online AI connected.
- The Market count covers the first 700 listings in the default order on one day. It is not a random sample of the 17,874 Expert Advisors listed, and descriptions change.
Frequently asked questions
Can you backtest an AI expert advisor? Only if the AI sits inside the EA. An EA that asks ChatGPT, Claude or a seller's server gets no answer in the MT5 Strategy Tester, because web requests are blocked there; in our run, 11 of 11 requests failed with error 4014.
Do AI EAs really use AI? Some do. Of 38 AI-named listings we read, 10 described where a model runs: 5 inside the EA, 5 online. 21 used AI only as a word.
Can an EA use ChatGPT or Claude? Yes, through a web request to the provider with your API key, after you allow the address in MetaTrader. That part cannot be backtested, and it adds the provider's cost and delay to every decision.
Why does the free demo of an AI EA look different from the live signal? The free demo on the MQL5 Market runs in the Strategy Tester. If the EA's AI is online, the demo runs without it.
Sources & further reading
Your next question
