Heavy, exotic particles interacting with matter and which can be directly detected through collider experiments are termed as stable massive particles or SMPs. More specifically a SMP is defined to be a particle that can pass through a detector without decaying and can undergo electromagnetic or strong interaction with matter. Searches for SMPs have been carried out across a spectrum of collision experiments such as lepton–hadron, hadron–hadron, and electron–positron. Although none of these experiments have detected an SMP, they have put substantial constraints on the nature of SMPs.