Discretionary vs Systematic Trading

Every trader sits somewhere on a line between two approaches. At one end, discretionary traders make decisions using judgement, reading charts, news and context and deciding trade by trade. At the other end, systematic traders follow precise rules that define every entry, exit and position size, often coded so a computer can run them. Manual trading, where a person clicks the buttons, can be either: a manual trader can still follow fixed rules. Understanding both helps you design an approach that suits you.

Definitions#

Discretionary trading#

A discretionary trader might see a breakout and decide to take it because the overall market is strong, the news is supportive and volume looks convincing. Another day, the same chart pattern might be skipped because of a feeling that something is off.

Strengths

• Can weigh information that is hard to code, such as unusual news or changing market behaviour.
• Adapts quickly to new conditions.
• Can be very effective for experienced traders with strong pattern recognition.

Weaknesses

• Hard to test, so it is difficult to know if there is a real edge.
• Open to every bias: Confirmation Bias, FOMO, Recency Bias and more.
• Results depend on the trader's state on the day. See Mental State Tracking.
• Hard to scale beyond what one person can watch.

Systematic trading#

A systematic rule might say: "Buy when the 20 day high is broken and the 50 day moving average is rising. Risk 1% of equity with a stop two ATRs below entry. Exit when price closes below the 20 day low." Anyone, or any computer, following these rules gets the same trades.

Strengths

• Can be tested on historical data before risking money. See Backtesting Methodology.
• Removes most in the moment emotion.
• Easy to apply to many markets at once, which helps diversification.
• Results are measurable and improvable.

Weaknesses

• Rules can be overfitted to the past and fail live. See Overfitting and Curve Fitting.
• Cannot react to events the rules do not cover.
• Following rules through long drawdowns is psychologically hard; many traders override their systems at the worst time.
• Building and testing systems takes skill and time.

The hybrid approach#

Many traders combine the two:

• Systematic setups, discretionary filters: rules generate signals and the trader can veto them for defined reasons, such as major news.
• Discretionary entries, systematic risk: judgement picks trades, but position size, stops and daily loss limits are fixed rules. See Position Sizing and Maximum Trade Risk and Daily Loss Limits.
• Rule based checklists: a Pre-Trade Checklist turns discretion into a repeatable process.

The fixed risk rules part matters most. Even highly discretionary professionals usually have strict limits on how much they can lose.

Which suits you?#

• Choose more discretion if you enjoy reading markets, can stay objective and are willing to keep detailed records to prove your edge.
• Choose more system if you like data and testing, struggle with emotions in the moment or want to trade many markets.

Systematic trading leads naturally to Quantitative Trading and Algorithmic Trading Explained.

Frequently asked questions#

What is discretionary trading?#

Trading in which each decision is made by the trader's judgement, using charts, news and context rather than fixed rules.

What is systematic trading?#

Trading by predefined rules that specify entries, exits and position sizes, so the same conditions always produce the same trades.

Is systematic trading better than discretionary trading?#

Neither is better for everyone. Systematic trading is easier to test and less emotional; discretionary trading adapts faster but is harder to verify.

Next, learn how data and models drive Quantitative Trading.