Mega Cap

A huge market cap company, i.e. one valued at some notionally mega amount like $100 billion or more. Mega Caps are a big deal for institutional investors because they often comprise such a large part of the index against which they are measured by their investors that they almost "have to" own those mega caps at least in part or, should the mega cap take off and do well, they'll lag noticeably. Google, Facebook, Coca Cola, Disney, Amazon. All Mega Caps.