What’s with this guy?

Read “Discussion Materials” by Bill Keenan

For some people (read: most of the high school and undergrad kids on here) this job is their entire life, so they have nothing else to discuss. 

Lol you could be describing one of my coworkers exactly. 

While I don't disagree with the top comment above, I think it's also highly possible that your colleague is just insecure (hence why he is always trying to figure out what you're doing) and copes with it by putting down others. I have found that most often, the people who are happy with themselves don't feel the need to put down or insult others. 

Sounds like he’s just socially awkward or doesn’t know how to ask what others are doing without sounding weird. He might be insecure about his own staffing and is just butt-sniffing to see what other people are on. I would just avoid talking about work and see if you can either spin the conversation positive or avoid talking to him

Am I the only one getting the "trying to be cutthroat competitive" vibes here? He's scoping intel on how late you work, what files you're working on etc. and 

People who always complain about stuff rarely understand how negative they actually are. What has worked for me is confronting them as this actually makes them realize that I have 0 interest in their negative views. "I actually really enjoy working with this industry due to X, Y and Z. I don't find it shitty at all" 

I know that guy well.  Have seen him a few times before.  Very familiar pattern.

He's insecure and doesn't really have a clear vision in his head of how a good banker adds value.  So he uses pointless rules of thumb (live is better than non-live, good industries are better, "robust" modeling indicates quality projects, staying late is important, etc etc) to help him gain some modicum of clarity around how to move toward success.

Either he will learn to become more thoughtful about the right way to add value, or he'll fail.  The ones I knew failed.

He may literally be autistic. This is a thing that some autistic people do in conversations. Basically internally applying "algorithms" to figure out how to respond to questions or statements that come up in conversation. Non-autistic people do this as well, to some extent, but they are usually able to more quickly figure out when certain responses are more vs less appropriate. Meanwhile, the autistic guys just go with a mix of whatever responses they see show up most often. Which, if they are surrounded by assholes, means they start to act like assholes.

Or he is just a regular guy who is also an asshole.

Kind of surprised at the amount of credit being given to this guy by most people here. I agree with the couple of above posters that interpret this as a cutthroat competitive person trying to gauge their position and demean other peoples’ work to make it seem like they’re the top of the heap. These people tend to fizzle out, and you should just not even entertain their questioning going forward.
 

I remember several people like that in my associate class - especially the first few months as an associate, what you get staffed on is borderline completely random, and staying late for the sake of staying late is a waste of time (senior people don’t care and your classmates’ opinions don’t matter). The first six months I was on the job, I happened to basically get no live staffings and nothing that kept me late, so I was routinely out the door by 7pm. My reputation in the class was that I was lazy and not particularly good. I did not care in the slightest, ended up being quite good at the job, and ended up top bucket every year from A2 - VP3.

As a general principle, you should view any criticism, no matter how hostile or ridiculous, as an opportunity to reflect and analyze - can you make things better? Would the improvement be worth your time and effort? For example, when he says there's no model - you should think to yourself, is there already a calculation that should be classified as a model and properly validated by 2LOD? Or is there an opportunity for you to develop a new model? Perhaps not, in which case youd have an answer ready if in the future someone else asks you why there's no model.But also, and especially if the criticisms are mostly unfair, you should worry about this guy badmouthing you to other people by repeating to them the same criticisms about you that he says to your face. You may want to avoid giving him any more ammunition/information than he needs to know, even if you need to be rude about it.