Should I major in Physics/Econ or CS/Econ?

Consulting CS is probably a better bet. HF in most cases, probably still CS. 

Physics is a hard major. You really should be passionate about it before deciding that you are going to double major

CS is a much more flexible major unless you hate the subject matter. If you're 50/50 do CS.

If you can handle physics, do physics. It's harder but there's much less supply of graduates and the demand is always higher.

I study Physics and I would suggested you do it ONLY if you are passionate about it and you are good at Maths. If you lack any of these 2 factors, you are going to have a really hard time. It’s a brutal course, but very rewarding in terms of the skillset that you will obtain out of it. Also, you will do a lot of different things (ranging from coding to presentations to article writing etc.) so you can become a well-rounded graduate. Many people here are...interesting (the general public would consider them crazy), so keep that in mind.

CS is more mainstream and less challenging. But the supply of graduates is much (much) higher. I am not sure how advanced their Maths are so I can’t really comment on how well it prepares you for that. Also, CS people have the reputation of being “ghosts” (ie. you never see them anywhere outside). I guess most of them are somewhat introverted but for quant positions that shouldn’t really be a problem(?).

I was in a very similar position to you. Did CS at a target school and was looking at Physics/Econ as a second major/minor. I'm gonna try to pitch that you should drop the Econ major and pick up the CS major.

CS - you can't really go wrong with CS. It opens a ton of doors into PM/SWE, quant trading, etc, all of which are arguably much preferable to consulting/IB. In addition, my experience during recruiting was that I got a lot of respect for a CS major from finance/consulting and actually had lower expectations during finance interviews, so those doors 100% remain open. Downside is that it is tough, but it's really not impossibly difficult. A few tough nights, sure, but you'll make it through.

Physics - gets you a ton of respect during recruiting like CS, but it's super tough. It also doesn't get you coding skills that would open doors for PM/SWE.

Econ - the value of an Econ degree is pretty low IMO, especially compared to Physics/CS. Econ major is mostly theory and doesn't really help for recruiting. You'll actually learn most of what you need on recruiting from UChicago's finance clubs. Yes, it checks the mark of 'business acumen', but doesn't do much else for you

What I ended up doing was CS and minor in Econ, which I found to be perfect for rigor and recruiting. I interned at a BB, said no for full-time, and ended up in tech at FAANG.

All said, I know you said you're 'set' on Econ, in which case I'd prefer CS as a second major/minor. But would definitely recommend doing the CS major and dropping Econ.

CS by far. Way more applications and demand for the skill set.