Scale In / Scale Out

(see also “room to add”) the practice of entering or exiting a trade with only a specified portion of desired lot size (such as 25 or 50%) instead of the whole lot size, with the intent of adding or closing additional entry(ies) if imminent price action continues to favor the applied strategy. For example, if a trader’s standard lot size is 100 shares, they may decide to take first entry with only 25% of lot size (in this case, trading 25 shares), with the intent to place additional 25‑share trades conditioned upon the price action continuing to move against the desired direction immediately after the first entry.

The trader may also intend to scale out of their positions, meaning exit, with only a specified portion of desired lot size (such as 25% or 50%). For instance, using the last example, the trader could exit their first portion with only 25% of their lot size, leaving 75 shares left after the first exit.