CS major bad for IB/S&T?

Lol no

1) you go to stanford so you can

major in anything

2) CS will make you stand out even more

Lol no. I went to a non-target as a computer engineering major and still got multiple IB/PE offers.

IB maybe, but you're at an IVY studying Comp sci. My suggestion is look into quant S&T. It's one of the most sought after fields in BB's and is extremely useful for moving to hedge funds after. You'll be fine tho with most likely whatever you choose, just make your grades are good and your golden lol.

Some traders are being asked to learn how to code on the side. In S&T, coding can only help you.

No it wouldn't hinder you. Curious as to why you're majoring in CS though. If you like CS for the typical reasons many people do (puzzle/problem-solving aspect of it, building projects, balance of creativity and logical thinking), you're not going to get much of that in IB, although quant roles could be good. Only saying this because I had buddies that studied CS and then went into banking and complained about not being "intellectually stimulated" or living up to their skills or whatever. tbf many people will experience this in banking, especially coming from top schools, but I saw the CS kids took it way worse for some reason.