Panic buying is an imprecise common use term to describe the act of people buying unusually large amounts of a product in anticipation of or after a disaster or perceived disaster, or in anticipation of a large price increase or shortage, as can occur before a blizzard or hurricane or government decree banning a particular popular product such as incandescent light bulbs. These goods are bought in large amounts to offset a potential shortage or as an act of safety.
Additional meaning of Panic buying:
While panic buying can result in a sudden increase in the cost of goods, it is distinct from looting as it does not entail theft or deliberate property damage.