stockbroker belt
noun [ C ] UK uk/ˈstɒk.brəʊ.kə ˌbelt/ us/ˈstɑːk.broʊ.kɚ ˌbelt/
（伦敦附近在伦敦商业区工作的富人聚居的）富人区，股票经纪人带
the area near London where many rich people live in large houses and from where they travel to work in the City (= the financial area of London)