Threshold switches with Ag or Cu active metal species are volatile memristors (also termed diffusive memristors) featuring spontaneous rupture of conduction channels. The temporal dynamics of the conductance evolution is closely related to the electrochemical and diffusive dynamics of the active metals which could be modulated by electric field strength, biasing duration, temperature, and so on. Microscopic pictures by electron microscopy and quantitative thermodynamics modeling are examined to give insights into the underlying physics of the switching. Depending on the time scale of the relaxation process, such devices find a variety of novel applications in electronics, ranging from selector devices for memories to synaptic devices for neuromorphic computing. Volatile threshold switches with Ag or Cu active metals in solid electrolytes feature electrical‐bias‐induced conduction channel formation and spontaneous rupture of the conduction channel upon cessation of the external bias, which shows unique delay and relaxation dynamics in conductance evolution and can be tuned for a variety of novel electronic applications, including selectors, synapses, neurons, true random number generators, etc.