What is a kill switch in trading?

A trading kill switch is one control that stops an automated system at once: no new orders and, depending on the design, the positions it opened are closed at the market price. What matters is exactly what a given switch stops, what it closes and what it leaves running.

Kill switch vs the other stops in MT5

MT5 has several ways to stop an Expert Advisor. They do different things:

The MT5 help is precise about the first row: with algo trading disabled, “scripts and Expert Advisors can work, but are not able to trade.” The bulk close is the Group operations item in the Trade tab’s context menu, and it only appears with One Click Trading enabled in Tools → Options → Trade (MT5 help). It closes everything on the account once, and does nothing about what an EA does next.

Why closing is the hard part

Stopping new orders is simple. Closing is a trade request like any other:

• It needs the market for that symbol open. On a weekend, closes on forex pairs fail until trading resumes.
• It fills at the market price, which in a fast market can be well past where you expected.
• If it works through an EA, it needs the terminal running and the Algo Trading button on.

The forex market hours tool shows when the market is open in your time zone.

A common mistake

Switching off Algo Trading straight after pressing a kill switch that runs through an EA. The EA then cannot send the closes. Press the kill switch first, check the positions are gone, and only then switch Algo Trading off if you want to. The MT5 Algo Trading button explains what the button does and does not do.

A kill switch is also different from a daily loss limit. The limit reacts to a number and blocks new trades. A kill switch is your decision, taken at any moment.

The PipWarden kill switch

PipWarden’s kill switch is a button on the account page of the dashboard, which works from a phone. One press:

• stops the bot and cancels any entry the EA has not placed yet, which the signal log records as “Kill switch active”;
• tells the EA to close every position the bot opened, identified by its magic number, at the market price;
• leaves your manual trades and other EAs’ trades alone.

If the EA is offline, it closes the positions as soon as it reconnects. If a close fails, for example with the market closed, the EA retries once a minute while the kill switch is on, and you get an alert if positions stay open. The bot stays stopped until you start it again. Like any EA, it needs MT5 running on a Windows PC or VPS to act. For a limit that stops new trades on its own, see how to set a daily loss limit.