You'll find most major finance corporations on Wall Street and within the Financial District in Manhattan. Well-known companies include Goldman Sachs, Morgan Stanley, Deloitte, BlackRock, JPMorgan Chase, Credit Suisse, Deutsche Bank, and Citigroup, just to name a few.
What does it mean to work on Wall Street?
Generally, Wall Street means finance, and more specifically, investment banking, hedge funds, mutual funds or other asset management firms. Generally you would not refer to retail banking as Wall Street, but some Wall Street firms, like JP Morgan, also do retail banking.