Halt trading¶

One action stops everything and keeps it stopped. Use it when you want trading to end now and you do not want to think about the details.

Do it¶

From the windowFrom a terminal

Where	Stops
A session's Halt button, in Sessions or Operations	that session
Tray → Halt trading	every running or frozen session, with the window closed

arvo-engine session halt --all "spread blew out"     # everything
arvo-engine session halt twin_cross@alpaca-live      # one session

The reason is optional and worth giving — it goes on the record and into the review, and in a week you will not remember.

What it does, in order¶

The order matters and is deliberate:

flowchart LR
    B["You halt"] --> G["**1 · Arm the gate**<br/><small>no new entry can pass</small>"]
    G --> F["**2 · Flatten**<br/><small>exit what is held</small>"]
    F --> R["**3 · Stay halted**<br/><small>a restart does not lift it</small>"]

    style G fill:#1f6feb,stroke:#1f6feb,color:#fff

The gate closes before anything is sold. If it flattened first, a rule firing in that instant could open a new position straight into the exit.

Then check it worked¶

A halt reports what it could not do — read the output

If the venue refuses an exit, the halt names the instrument rather than reporting success. Those positions are still yours, and nothing is watching them any more.

arvo-engine session list

A halted session stays up briefly to book its exits' fills, then sits halted. Confirm at the broker that the account is flat before you walk away — Arvo tells you what it asked for, and the broker is the authority on what happened.

It stays halted¶

A restart does not lift it. A new session will not start under it. A person clears it deliberately.

A session the gate halted on its own — on a position the venue already held when it started, or on the drawdown limit — stays up, halted, and takes the kill switch like any other: what it holds is flattened through the session and lands on the record, rather than being closed at the venue by hand.

That is the point: a limit a restart lifts is not a limit. If halting were something a crash could undo, it would not be a safety control.

Stop versus halt¶

	Stops the rule	Exits positions	Survives a restart
Halt	yes	yes	yes
Stop	yes	no	no

stop ends a session and leaves the book alone — right when you are done for the day with nothing held, wrong when something is open. If you are unsure which you want, you want halt.

The drawdown halt is a different thing¶

The risk gate halts a session on its own when drawdown reaches the model's limit. That is not the kill switch and does not lift for anybody, including you — the model has to change for trading to resume. The risk gate →

When a session freezes — a freeze is not a halt; it is Arvo saying it is unsure what it holds and waiting for you.