Programmatic access to a broker's order system via REST, FIX, or WebSocket — for custom platforms and high-frequency strategies.
API trading bypasses the broker's GUI entirely. Used by developers, hedge funds, and serious individual quants. Most major brokers expose REST + WebSocket APIs; ECN brokers also offer FIX (institutional-grade).
Also called: broker API
Open full pageRunning a strategy on historical data to estimate how it would have performed — the first step in strategy validation.
Backtesting reveals whether a strategy has historical edge before risking real money. It's also the easiest place to lie to yourself — curve-fitting parameters until the equity curve looks great is trivial and meaningless.
Also called: historical testing
Open full pageModern multi-asset trading platform by Spotware — popular with ECN brokers for its Level 2 depth and cAlgo automation.
cTrader is often considered the closest retail equivalent to institutional ECN platforms. Level 2 depth, advanced charting, cBots (C# automation), and a clean modern UI.
Also called: cTrader Web
Open full pageA user-written or downloaded MetaTrader indicator that calculates and plots data not available natively.
Custom indicators extend MT4/MT5 with anything from variations on standard indicators (e.g. RSI with divergence alerts) to entirely new tools (volume profile, market regime classifiers).
Also called: indicator
Open full pageAn automated trading program for MetaTrader — opens, manages, and closes trades based on coded rules.
EAs run inside MT4 or MT5, monitoring price tick-by-tick and executing the trading logic the developer wrote. They can be 100% automated, semi-automated (signals only), or trade-management aids.
Also called: EA, robot, trading bot
Open full pageFinancial Information eXchange — the institutional-grade messaging protocol for low-latency order entry.
FIX is the standard protocol banks and ECNs use to communicate. It's faster than REST/WebSocket but more complex to implement. Retail traders typically need a 'Pro' or institutional account to access broker FIX gateways.
Also called: FIX
Open full pageRunning a strategy on live (or paper) data going forward — the only honest test before committing real capital.
Forward testing exposes everything backtesting hides: real spreads, real slippage, real broker quirks, and the trader's own emotions. A strategy that survives 3+ months of demo forward-testing has earned a small real-money allocation.
Also called: live testing, paper trading
Open full pageThe round-trip time between sending an order and receiving confirmation — critical for scalpers and HFT.
Total latency = network latency (you to broker server) + broker internal latency + liquidity provider latency. Retail traders typically see 50–300ms; co-located institutional traders see microseconds.
Also called: execution latency
Open full pageA venue or aggregator that gathers buy/sell interest from multiple participants, providing tighter spreads and deeper books.
In FX, liquidity is fragmented across banks, ECNs, and prime brokers. Liquidity pools (or LPs) aggregate these sources so retail brokers can offer one combined price.
Also called: LP, liquidity provider
An ECN broker connects to 12 bank/non-bank LPs. When you buy EUR/USD, the broker auto-routes to whichever LP shows the best ask in that microsecond.
The most widely used retail forex trading platform — supports charting, EAs (MQL4), and custom indicators.
MT4 (MetaQuotes, 2005) became the de facto retail FX platform thanks to free licensing, broad broker support, and an enormous library of EAs and indicators.
Also called: MT4
Open full pageMetaTrader's successor platform — multi-asset, more timeframes, better backtester, MQL5 language.
MT5 adds: native support for stocks/futures/crypto via broker, an economic calendar, depth-of-market, more order types, partial fills, and a vastly improved strategy tester (multi-currency, multi-threaded).
Also called: MT5
Open full pageTrading from a smartphone or tablet via dedicated apps (MT4/MT5 mobile, cTrader mobile, broker apps).
Mobile trading is fine for monitoring positions and emergency exits; less suited to complex order management or chart analysis. Most pros use mobile as a complement to desktop, not a replacement.
Open full pageMetaQuotes Language 4 — the programming language for indicators, scripts, and Expert Advisors on MT4.
MQL4 is a C-style language with built-in trading functions. Less strict than MQL5 (looser typing, fewer object-oriented features) but with an enormous codebase from the platform's two-decade install base.
Also called: MetaQuotes Language 4
Open full pageMetaQuotes Language 5 — the more powerful, object-oriented language for MT5 indicators, EAs, and scripts.
MQL5 is closer to C++ — full OOP, namespaces, templates, generics, and a richer standard library. EAs written in MQL5 can use the much-improved multi-threaded strategy tester.
Also called: MetaQuotes Language 5
Open full pageTuning a strategy's parameters to maximise historical performance — risky because it often produces strategies that fit the past but fail forward.
Optimization is necessary but dangerous. The more parameters you tune, the more likely you're fitting noise rather than signal. Defences: keep parameter count small, use walk-forward analysis, hold out a true out-of-sample period, and prefer parameter robustness over peak perform…
Also called: curve-fitting, over-optimization
Open full pageA small MQL program that runs once when attached to a chart — used for one-off tasks like closing all open trades.
Unlike EAs (which run continuously) and indicators (which calculate every tick), scripts execute once and exit. Common scripts: close-all, set-stop-loss-on-all-trades, place-grid-of-pending-orders.
Open full pageEvery individual price change (bid + ask) the broker recorded — the highest-resolution market data available.
Tick data is essential for scalping strategies and accurate backtesting. MT5's strategy tester runs on tick data; MT4's defaults to 1-minute candles unless you import tick data from sources like Dukascopy or Tickstory.
Open full pageA general term for any automated trading program — synonymous with EA in the MetaTrader world.
Bots range from simple if-then rule engines to ML-driven systems. Quality varies enormously; the marketing-to-substance ratio in the retail-bot industry is notoriously high.
Also called: robot, auto-trader
Open full pageWeb-based charting platform with social features and Pine Script — increasingly used for FX execution via broker integrations.
Originally a charting-only service, TradingView now integrates with brokers (OANDA, FOREX.com, Pepperstone, etc.) for direct execution. Pine Script is its native scripting language for indicators and strategies.
Also called: TV
Open full pageA remote server used to host EAs 24/7 — eliminates dependence on a home computer and reduces latency to the broker.
Running EAs from a VPS keeps them online even if your home PC reboots or loses internet. Choosing a VPS in the same data centre as your broker (Equinix LD4 for many London brokers) can reduce execution latency from 100ms+ to single-digit ms.
Also called: forex VPS
Open full pageA browser-based trading platform — no download required, runs on any device with a modern browser.
Most brokers offer a WebTrader option (often a JavaScript wrap of their main platform). Useful for traders on locked-down work computers; limited compared to native platforms for serious automation.
Open full page