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Stopping trading

Three levels of stop, least to most drastic. Pick by how much you trust the system right now.

Everything here works whether or not the engine is running. Halt state is a file under the state root, and flatten talks straight to the broker — so a wedged engine, a hung process, or a machine you have already killed does not stand between you and stopping.

Level 1 — halt one strategy​

Use when a strategy is behaving oddly but you have no reason to distrust the positions.

tradeflow halt VolumeSpikeStrategy --reason "entries look wrong since 14:00"
  • New entries for that strategy are refused.
  • Existing positions stay open, and their broker-side bracket legs stay protective.
  • Exits still work — see below.

Level 2 — halt everything​

Use when something system-wide looks wrong and you want to think before acting.

make halt REASON="feed quality"        # or: tradeflow halt all --reason "..."
tradeflow halts                        # what is currently in force

Positions remain open. Nothing is closed.

Level 3 — flatten​

Use when you do not trust the system, or a strategy is losing in a way you cannot diagnose quickly.

make flatten REASON="unexplained drawdown"
# or: tradeflow flatten --confirm --reason "..."

In this order, deliberately:

  1. Halt — recorded first. Cancelling and closing while an engine is still streaming bars is a race the engine can win: it re-enters on the next bar and the account refills behind you.
  2. Cancel every open order.
  3. Close every position.

Every step is attempted even if an earlier one failed, because a partial flatten beats stopping halfway and leaving positions open. The report says exactly which steps succeeded, and the command exits non-zero if any did not.

A halt never blocks an exit​

Halts refuse entries only. This is deliberate and worth understanding, because it is the difference between a switch you will pull and one you will hesitate over:

  • A halt that also blocked closing orders would trap the book at exactly the moment someone decided to stop.
  • flatten sets a halt and then closes positions. If the halt blocked exits, it would deadlock against its own gate.

Resuming​

tradeflow resume all                   # or a strategy name

Then restart the engine. Nothing resumes on its own — that is the point of the state being durable.

After a flatten​

  1. Verify at the broker that you are actually flat. The report is what this system believes; the broker is what is true.
  2. tradeflow halts — confirm the halt is in force.
  3. tradeflow reconcile — compare the ledger against the account.
  4. Diagnose, fix, then tradeflow resume all.

Practise it​

Run a flatten drill on paper, roughly monthly, while actually holding a position:

tradeflow flatten --confirm --reason "monthly drill"

Check that the position closed, tradeflow halts shows the halt, and resume clears it. An emergency procedure nobody has run is a procedure nobody knows works — find out on a day you chose, not on the day you need it.

What stopping does not do​

  • It does not close positions you opened by hand outside the engine; close those yourself.
  • It does not stop the engine process. Use Ctrl-C for that.
  • It does not undo fills. Slippage is real and irreversible.