Understand order execution¶

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A submitted Order is a request, a filled Trade is a lot, and Position aggregates the currently open lots. The trading reference contains order parameters and examples for cancellation, stops, OCO, and target positions.

From signal to fill¶

Existing eligible orders are processed against the new bar.
Order/fill notifications are delivered.
next() reads the visible history and submits new requests.
With the default next_open timing, new requests can execute no earlier than the following bar.

same_close processes new unconditional market orders from next() at that close. It does not let new limit/protective orders use the bar's already-observed High/Low. Orders submitted in event callbacks are not matched recursively.

Manage risk in the correct units¶

Expression	Meaning
`buy(qty=2)`	Add two asset units
`buy(amount=2000)`	Add a notional budget of 2,000 settlement-currency units
`buy(percent=20)`	Add a budget of 20% of request-time equity
`order_target_percent(target=0.2)`	Target a net position worth 20% of request-time equity
`trade.set_trailing_stop(percent=0.05)`	Trail by a 5% distance
`trade.close(portion=0.5)`	Submit an exit for half the lot

Budgets convert into fixed quantities at submission and exclude fees. A gap can cause rejection or an execution value different from that budget. reduce_only=True requires explicit quantity and cannot open new exposure.

Protection and OHLC ambiguity¶

sl and tp are absolute prices. Initial protection activates after entry. For conditional or same-close entries, it cannot use earlier High/Low information from the same bar. If a bar reaches both SL and TP and the path is unknown, SL takes precedence and an ambiguity is recorded. Stop execution can gap beyond the stop price.

Native trailing stops ratchet after favorable price movement for later bars. Partial exits cancel/rebuild protection for the remaining quantity. Canceling protection does not close the position.

End of data¶

The default mark_to_market policy cancels pending orders and retains open lots valued at the last close. close_at_last_close instead liquidates existing holdings and charges costs. It does not fabricate fills for final-bar entries that never reached an eligible execution phase.

Read result["_fills"] for executions, result["_order_events"] for status changes, and result["_open_trades"] for remaining exposure. Signal counts and order counts are not trade counts.

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