What is Blockbusting?

Legal Definition
Blockbusting was a business process of U.S. real estate agents and building developers to convince white property owners to sell their house at low prices, which they did by promoting fear in those house owners that racial minorities would soon be moving into the neighborhood. The agents then sold those same houses at much higher prices to black families desperate to escape the overcrowded ghettos. Blockbusting became possible after the legislative and judicial dismantling of legally protected racially segregated real estate practices after World War II. By the 1980s it largely disappeared as a business practice, after changes in law and the real estate market. After the turn of the millennium, claims were made that a similar but inverse practice was occurring in New York State and New Jersey on behalf of orthodox Jews, who were pressuring non-Jews into selling based on the fear they will be outnumbered by Jews, and subsequently resold at a much higher price to Jews.
-- Wikipedia
Legal Definition
Helping individuals into areas outside of their ethinic background. The current residents will sell and lower the prices of homes. A broker can buy their property for cheap and sell for higher prices.