GM’s Pam Fletcher is coming to TC Sessions: Mobility 2021 to talk about how to build a startup GM might be best known for the millions of Buick, Cadillac, Chevrolet and GMC-branded vehicles it designs, produces, finances and sells each year. But it also has a burgeoning incubator, where a team of 600 employees are working to develop 20 new businesses with a total addressable market of about $1.3 trillion. A few of the first startup fruits have already come to bear, including OnStar Guardian, OnStar Insurance, GM Defense and most recently, BrightDrop — the commercial electric vehicle delivery business that launched in January.