Ma'anar ƙamus na oligopoly tsarin kasuwa ne wanda ƙananan ƙananan kamfanoni ke mamaye kasuwa don wani samfur ko sabis. A cikin oligopoly, ayyukan kamfani ɗaya na iya yin tasiri mai mahimmanci akan sauran, kuma galibi akwai manyan shinge don shigarwa ga sabbin kamfanoni waɗanda ke ƙoƙarin shiga kasuwa. Oligopolies na iya haifar da raguwar gasa, farashi mai girma, da ƙarancin fitarwa idan aka kwatanta da ƙarin kasuwanni masu gasa. Misalan masana'antun oligopolistic sun haɗa da motoci, sadarwa, da masana'antar banki.