An automated trading system is software that opens, manages, or closes trades according to defined rules. It may run inside a trading platform like NinjaTrader, TradeStation, MultiCharts, MetaTrader, or TradingView, or it may connect through an API such as Interactive Brokers TWS.
The best systems are not mysterious. They are specific. They define what to watch, when to act, how to size the trade, and what to do when conditions change.
For a full planning workflow, read the automated trading strategy development guide.
Core parts of an automated trading system
Most systems include four major pieces.
Entry rules
Entry rules define when a trade should begin. They may use indicators, price levels, time windows, volatility, volume, order flow, or custom calculations.
Good entry rules also define what should block a trade. Filters are often just as important as signals.
Exit rules
Exit rules define how the trade should end. This may include stops, targets, trailing logic, time-based exits, indicator exits, or manual override behavior.
Exit logic should be defined before development starts. Otherwise, the system may enter correctly but manage risk inconsistently.
Trade management
Trade management covers what happens after the position is open. Examples include moving stops, scaling out, adding to a position, flattening at a specific time, or reacting to rejected and cancelled orders.
This is where live platform behavior matters. A system should account for order states, reloads, partial fills, and disconnects.
Position sizing
Position sizing determines how many contracts, shares, or lots the system trades. It may be fixed, account-based, volatility-based, or tied to a user-defined risk amount.
Sizing should be explicit. It should not be left as an assumption inside the code.
Testing before live use
Automated systems should be tested in stages.
Start with a code-level logic review. Then run historical tests to check whether the rules fire when expected. After that, use simulation or replay to observe order handling under more realistic conditions.
The purpose of testing is not only to review performance numbers. It is to confirm that the system behaves correctly when the market is moving, when orders are rejected, when sessions change, and when the platform reloads.
Do automated trading systems work?
Automated trading systems can work when the rules are sound, the testing is realistic, and the trader understands the limits of the platform and market. They can also fail quickly when the rules are vague or the backtest depends on assumptions that do not hold in live trading.
The practical question is not whether automation works in general. The question is whether this specific system follows clear rules under realistic conditions.
When to hire a developer
Consider hiring a developer when the logic is important enough that reliability matters, the platform behavior is complex, or the existing code is difficult to maintain.
Before requesting a quote, gather the platform version, chart setup, screenshots, current code, expected entries and exits, and examples of edge cases. A clear scope makes the project easier to price, build, and test.