Shares opened at $42 on Tuesday before declining, valuing the grocery delivery company at $11.1 billion.

Read More Delivery Services, Venture Capital, Supermarkets and Grocery Stores, Computers and the Internet, Start-ups, Freelancing, Self-Employment and Independent Contracting, Mobile Applications, Initial Public Offerings, Instacart, Mehta, Apoorva, Simo, Fidji