Walmart, Kroger, Costco, and Albertsons are the most frequently visited grocery stores in the nation, comprising a whopping 69% of the grocery market. What seems like healthy market competition devolves into an oligopoly when we account for the fact that these supermarkets are heavily influenced by the same 3 companies. Blackrock, Vanguard, and State Street, the big 3 of investment banking, own the most shares of Walmart, Kroger, Costco, and Albertsons. Which effectively shifts market power away from consumer interests.