De-peg refers to a stablecoin's market price deviating from its target peg value. For a USD-pegged stablecoin, 1 coin normally equals $1; when market price drops to $0.95 or rises to $1.05, a de-peg has occurred. De-pegs can be temporary (hours to days, recovering after market correction) or permanent (issuance mechanism collapses, unable to recover). The consequences are vastly different: the former has limited impact; the latter can result in total principal loss for holders. Key factors for assessing de-peg severity: deviation magnitude, duration, and whether the issuance mechanism still functions.