Backtesting & Validation
How Backtesting Works, And What It Can't Tell You
Backtesting replays a strategy against historical data. What the process does, why results look better than they were, and how to read a report honestly.
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Risk Automation
Position sizing, exposure limits, order gates and kill switches, how risk is enforced by systems rather than intention.
Definition
Trending- What is risk automation?
- Risk automation is the enforcement of trading limits by software rather than discretion, applying position sizing, exposure caps and pre-trade checks to every order regardless of what a strategy requested.
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Understanding risk automation
Risk automation is the difference between having rules about risk and having risk limits that hold. A position-size rule that a trader can override in the moment is a preference. The same rule implemented as a gate every order passes through is a constraint, and only the second one survives a bad afternoon.
Implemented properly it sits between strategy and execution as a separate stage, not inside the strategy. That placement is the point: if sizing and exposure checks live in strategy code, a defect there can produce an order no limit would have permitted, and the limits were never really limits. As an independent gate, the checks hold regardless of what the strategy asked for.
It also concentrates the controls that matter in an emergency into one place. A kill switch in the gate stops new entries across every strategy by flipping one flag, without a deploy and without editing strategy logic. The value of that is measured entirely in situations nobody planned for.
Common questions
- What should a pre-trade risk check actually verify?
- At minimum: that the order is within the per-position size limit, that total exposure after the fill stays inside the account cap, that per-strategy capital has not been exhausted, and that the kill switch is not engaged. Each is a rejection with a stated reason, not a silent adjustment.
- Does automating risk controls reduce risk?
- It removes one specific source of loss, the limit that was not applied because a human chose not to apply it. It does nothing about strategy risk, market risk or the possibility that the limits themselves were set badly. Enforcement and calibration are separate problems.
- Where does position sizing belong?
- In the risk layer, computed from account state at the moment of the order, not hardcoded in the strategy. Sizing depends on capital and current exposure, which the strategy deliberately does not know about, and that separation is what lets the same strategy run at different capital levels.
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Put this into practice
Describe a strategy in plain language, backtest it against historical data, and paper trade it before any capital is committed.