What it is
A set file (short for settings file) is a small text file that stores all of the configuration settings for an Expert Advisor. Instead of manually entering every input parameter each time you attach an EA to a chart, you load a set file and all the settings are applied instantly.
Set files are how EA developers share their recommended configurations, and how traders save and reproduce specific setups across different accounts or platforms.
How it works
Every Expert Advisor has a list of input parameters — variables the user can adjust to change how the EA behaves. These might include things like lot size, stop loss distance, take profit level, which currency pairs to trade, which trading sessions to be active in, and dozens of other settings depending on the EA's complexity.
A set file saves all of these values in a simple text format. The file has a .set extension and lives in a specific folder inside the MetaTrader data directory.
What a set file looks like
A typical set file contains lines like:
LotSize=0.01
StopLoss=50
TakeProfit=100
MaxTrades=3
TradingSession=London
MagicNumber=12345Each line is a parameter name and its value. The EA reads these when it starts and applies them automatically.
How to load a set file
- In MetaTrader, right-click the chart with the EA attached and select "Expert Advisors" → "Properties" (or double-click the EA icon in the chart corner)
- The EA settings window opens — click the "Inputs" tab
- Click the "Load" button at the bottom
- Navigate to the set file and click Open
- All values update automatically — click OK to apply
Why it matters
Set files matter for three practical reasons:
- Consistency: Running the exact same settings across multiple accounts or reinstalling after a VPS migration is simple — just load the set file rather than re-entering dozens of values manually, which introduces human error.
- Version control: If you change settings and the EA performs worse, you can revert to a saved set file immediately.
- Developer recommendations: When you buy an EA, the developer typically provides set files — one per currency pair or trading style they've tested. These represent their recommended settings rather than the raw defaults.
Common misconceptions
- The default settings are not always the best settings. EA defaults are typically conservative starting points. Set files from a developer represent their tested and recommended configurations — always use the provided set files rather than running on defaults unless you know what you're changing.
- Set files are EA-specific. A set file from one EA will not work with a different EA, even if they look similar. The parameter names must match exactly.
- Changing one setting can dramatically change EA behaviour. Something as simple as adjusting the lot size multiplier or the number of maximum open trades can completely alter the risk profile. Always understand what a parameter does before changing it.
The Karnek note
Karnek is read-only monitoring for MetaTrader - it watches every account you run, live on one dashboard, and alerts you the moment something stops. It never trades and never asks for a trading password.
Written and reviewed by the Karnek Research team. Last updated August 2026.
Educational content only - not financial advice. Past performance does not predict future results. Trading carries significant risk.