holdout

Holdout is a term used to describe a person or party that withholds agreement, payment, or participation until certain demands are met, typically delaying or blocking a negotiated settlement or transaction. The word is used across fields such as negotiations, finance, data science, and real estate.

In mergers and acquisitions, a holdout may refuse to approve a deal, pressuring for sweeter terms; can hinder or derail the transaction; sometimes used strategically by activist investors and other interested parties in related negotiations.

In debt restructurings, holdout creditors refuse to participate in a plan, complicating restructuring; their actions can increase costs or delay agreement; specialists may pursue litigation or financial incentives.

In statistics and machine learning, a holdout set, or holdout sample, is a portion of data reserved for evaluating a model's performance; it should be separate from training data to provide an unbiased assessment; cross-validation is related.

In real estate, a holdout property or holdout buyer refers to a property or buyer who refuses to participate in a development or sale; in marketing research, a holdout group is kept separate from treatment groups to measure effects.