Expert Advisor and MetaTrader terms, explained.

A TradingView notification that runs on TradingView’s servers and fires when its saved condition is met. It keeps the script inputs it was created with, even if you change the chart afterwards.

A simulation of trading rules on historical data. It shows how the rules behaved under the tester’s assumptions about prices, costs and fills, not what an account earned.

The decline of the account balance from an earlier balance peak. The balance changes only when a position is closed, so open losses are not in it.

A broker fee charged per trade or per traded volume, separate from the spread. Before comparing results, check whether a reported profit already includes it.

The decline of equity from an earlier equity peak. Equity includes the profit and loss of open positions, so this figure shows losses that the balance does not show yet.

A program for MetaTrader 4 or MetaTrader 5 that watches prices and can send trading requests according to the rules in its code. It trades only while its terminal runs with algorithmic trading allowed.

An informal name for an Expert Advisor, taken from the market where EAs became popular. “Trading bot” is the wider word for an automated trading program on any platform.

A run of unchanged rules on data that was not used to build them. On a demo or live account it uses new market data; in the MT5 Strategy Tester, “Forward” means a later part of the selected history.

A position logic that arranges entries across price levels. Each further entry adds exposure while earlier trades remain open, even when every entry has the same size.

An MT5 account mode in which separate positions can exist on one symbol, including opposite ones. To close one, the EA has to select that position; an opposite order opens another.

A program that calculates values and draws them on a chart. A MetaTrader indicator cannot send orders; you decide what to do with what it shows.

The ratio that sets how much margin a position needs. Higher leverage lets the same balance open more volume; it does not change what a price move gains or loses per lot.

The unit of trade volume. One lot stands for the number of units given as the contract size in the symbol’s specification.

A magic number is the ID an Expert Advisor attaches to its trade requests in MetaTrader 5. It labels trades for filtering; it does not reserve them.

Account money reserved while a position is open. Free margin is what remains for further positions.

The margin level at which the account needs to be replenished. The stop out level is the separate threshold at which positions are closed by force.

A sizing rule that increases the trade size after losses. Combined with a grid, the open volume grows much faster than with fixed sizes.

The programming languages of MetaTrader 4 and MetaTrader 5. An EA is written and compiled for one platform; a compiled file does not run on the other.

An MT5 account mode that keeps one position per symbol. A further fill on that symbol increases, reduces, closes or reverses the existing position.

Data that was not used to choose or tune a strategy’s rules. A result on such data is a check of the finished rules; once you adjust them after looking at it, the data is no longer out-of-sample.

Tuning rules or parameters until they match one stretch of history. The result looks strong on that data and says little about data the rules have not seen. Also called curve fitting.

A TradingView script that adds simulated orders and a performance report to a chart. It does not send those orders to a brokerage account by itself.

A trader convention for a price step, not a MetaTrader unit. On a EURUSD quote with five decimals, one pip is 0.0001, which is ten points.

A point is the unit MetaTrader uses for price distances on a symbol. A pip is a trader convention: on a five-decimal EURUSD quote, one pip is ten points.

A paid evaluation on a simulated account with a profit target and loss limits. Whether and how an EA may be used depends on the firm and the product.

With real ticks, the MT5 Strategy Tester replays ticks stored by the broker instead of generating them from minute bars. The orders are still simulated.

An indicator repaints when a value or marker it showed on an earlier bar changes or disappears later. The finished chart then looks better than what was visible in real time.

The broker’s answer in instant execution when it does not accept the requested price: it returns the prices at which the order can be executed instead of filling it.

A MetaTrader program that performs one task and is then unloaded. An EA, by contrast, stays on the chart and keeps reacting to new prices.

A word with several meanings: a line an indicator draws, an alert, a message in a chat group, or MetaTrader’s copy-trading service. Only the last places trades on your account.

Slippage is the gap between the price an order asked for and the price it was filled at. An EA’s deviation setting limits it only in some execution modes.

The difference between the ask and the bid price. MetaTrader reports it in points, and the symbol specification says whether it is floating.

The stop out level is the margin level at which a MetaTrader account’s most unprofitable position is closed by force. Brokers set it in percent or money.

The MetaTrader tool that runs an EA on historical data. What its report means depends on the modelling mode, the data and the cost settings of the run.

Swap is the amount charged or credited when a position is carried into the next trading day. MetaTrader lists it per symbol, with a multiplier per weekday.

A new price quote for a symbol. In MetaTrader, the arrival of a tick is the event that makes an EA check its rules.

The smallest change in volume a symbol accepts, set by the broker together with the minimal volume. An EA has to round a calculated lot size to it.

A rented remote computer that stays switched on. Traders use one to keep a MetaTrader terminal and its EAs running while their own computer is off.

An HTTP POST request that TradingView sends to an address you choose when an alert fires. It delivers a message; whether an order follows depends on the service that receives it.