cornering the market

Situation where an individual, firm, or cartel controls the supply of a commodity and dictates its price. Because cornering is often ruthless in its anti-social behavior, governments enact anti-monopoly or anti-trust laws to prevent its occurrence. Attempts to corner a market, however, do not usually last long because high prices encourage people to unearth the untapped supplies and create substitutes which 'break' the corner. See also Black Friday.