API access versus clicking: where the milliseconds go

[Fairman]

API access versus clicking: where the milliseconds go

A manual trader sees a signal, moves a hand, clicks a button, and the order travels to the broker. Human reaction time alone adds 200 to 300 milliseconds, often more.

An automated system sends an order the instant the condition is met, usually in a few milliseconds. For strategies that depend on tiny, fleeting edges, the difference decides whether the trade exists at all.

But speed is only part of the story. Automation executes bad decisions just as fast and has no sense of context. A script keeps trading through news, spread spikes, and feed problems unless it has been told what to avoid.

APIs also bring their own limits: rate caps, connection resets, and authentication timeouts, all of which need handling in code.

For many scalpers, a hybrid works well: automation for entries that depend on speed, and manual judgement for supervision and for stepping aside in odd conditions.

A common stepping stone is a semi-automated setup, where a script handles the order mechanics, such as placing the order, the stop, and the target in one keypress, while the decision to trade stays manual. It captures most of the speed benefit with little of the risk.

Which parts of the process are manual, and which would benefit most from automation?