A middleman minority is a minority population whose considerable occupations are somewhere in between the producers and consumers: traders, money-lenders, etc., hence the word "middleman" in the term. A middleman minority, while possibly being a subject to discrimination, does not hold an "extreme subordinate" status in society.
The book World on Fire: How Exporting Free Market Democracy Breeds Ethnic Hatred and Global Instability introduces a similar concept of market-dominant minorities.
There are numerous examples of such groups gaining eventual prosperity in their adopted country despite discrimination. Often, they will take on roles between producer and consumer, such as trading and moneylending. Famous examples such as Jews throughout Europe even at times when the discrimination against them was at their peak such as during World War II they still had great success in some parts of Europe, Chinese throughout Southeast Asia, Parsis in India, Igbos in Nigeria, Indians in East Africa, Lebanese in West Africa, people from the Soviet Blocs in the USA during the Cold War, and many others.
Stereotypically, middleman minorities are thrifty and save a large portion of their incomes, and have limited interaction with the native population in a country. Education is placed at a high premium among all of these groups. These groups usually become the most successful ethnic groups in a society soon after they immigrate, even though they are often poor when they first arrive. Middleman minorities usually provide an economic benefit to communities and nations and often start new industries. However, their economic aptitude, financial success, clannishness, common prejudices and paranoia against businesses and moneylending among other groups, and often disproportionate representation in universities and in politics, high representation in commerce and some high end white collar professional and managerial positions can cause resentment among the native population of a country. Middleman Minorities can be victims of violence, genocide, racialist programs, or other forms of repression. Other ethnic groups often accuse them of plotting conspiracies against their nation or of stealing wealth from the native population.