Can you stop a trading bot instantly?
What instant stopping requires architecturally
Stopping fast is an architecture, not a button. The stop control has to live between the strategy and the broker connection, checked before any order can move, so that a confused, hung, or misbehaving strategy is still stoppable. It has to fail closed — if the system cannot read the switch, it must not trade. And it has to be reachable when you are panicking on a phone, not just from a terminal at home.
Our own desk stack is built around exactly this: a gated runner that checks the global kill switch every cycle, one switch to go live, one switch back to paper. Stopping is the most exercised code path in the system, on purpose.
- In the order path: off means no order flow, regardless of strategy state.
- Fails closed: unknown switch state means stop.
- Reachable: works from your phone in seconds, not your desk in minutes.
- Layered: strategy pause, desk kill switch, broker-level API revocation, compartment defunding.
The stop test to run before you buy
Ask any vendor to demonstrate the stop, live, mid-cycle. Time it. Then ask the follow-ups: what happens to open orders when the switch flips? What happens to open positions? Can the bot restart itself, or does resuming require a deliberate human act? The answers should be immediate, specific, and boring.
Also rehearse your own layers: know how to flip the desk switch, how to revoke the API connection at the broker, and how to defund the compartment. Three independent ways to stop, none of which depend on the vendor being awake.
First-party data — from our own desk
More questions people ask
What happens to open positions when I stop a bot?
Stopping halts new activity; existing positions remain yours to manage in your brokerage account. A good desk documents this explicitly so there are no surprises.
Can a bot restart itself after I stop it?
It must not. Resuming should require the same deliberate human action as going live in the first place — anything that un-stops itself does not have a kill switch, it has a snooze button.
Is broker-level revocation enough on its own?
It is a strong backstop, but you want it as the second layer, not the only one — the desk's own switch is faster and does not depend on finding a settings page under stress.
Regulator resources and sources
Independent, official reading — not affiliated with EB28:
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