OCA exit groups, trailing limits, and ATR stops

A stop is a precondition of entry

A protective stop is treated as a precondition of entry because trade size is limited by the distance from the entry price to that stop. ATR position sizing is a volatility-scaled stop or trail distance, based on average true range, that keeps loss and exposure bounded before and during the trade.

Trail a limit, then a market stop

When price moves in the trade's favor, the stop is advanced. A trailing stop is a stop that advances with favorable price and, when triggered, typically sends a market exit. A platform trailing stop then typically sends a market order if price later hits the stop.

A trailing limit is preferred when liquidity allows because a trailing stop's market order can add slippage after the stop price is hit. A limit order names an acceptable fill price so an exit can avoid a market cross when liquidity is present. A trailing limit follows price at a set offset and can miss the exit if price jumps through it, so a trailing stop can sit a few cents beneath the trailing limit as a backup.

One group can hold more than two exits

One-cancels-all is a linked order group in which a fill on any child cancels the remaining children. One-cancels-all groups can hold more than a two-leg target-and-stop pair; a fill on any child cancels the remaining exits. Hard, non-trailing stops can be stacked beneath a working stop so a large gap that skips the nearer limit still meets a farther protective price. A hard stop is left in place for gap or overnight risk.

Stacked prices in a long example

In the worked long example, protective levels sit at 42.75, then 42 for a large downside gap, then 41 so a still-larger gap can still exit near the 40.75 entry.

Default trail and a tighter unused window

A default trailing pair uses a minus-one-ATR trigger, a limit one cent below that trigger, and a market stop three cents below the limit trigger. A tighter trailing pair can stay inactive until a higher price such as 44.80 is reached inside a defined session window, then expire at that session's close if unused.

Match overfill-protection on every child

Every order in the cancel-all group must use the same overfill-protection setting so a fill cannot leave leftover size working.