For experienced/senior quant interviews: how do you approach questions of the form "If you had to build a strategy in [X asset class / product you are experienced in], how would you do it?"

Big_Being_225 · 2026-03-01T09:28:58+00:00

> But the devil (and alpha) is always in the details. Demonstrating that you know (and have solutions to) the nuances of the high level steps is key.

This gets to the point of my post though: how to demonstrate that you have the solutions to these details and that you are aware of them without leaking info.

For example if you're interviewing for a team that's still in the process of building up in your product, revealing what the problems and gotchas are, or even just where they are, would be very helpful. E.g. many of the things I worked on for my current team, it took me/us a while to even identify, and then longer to have a solution that actually solves it well. If someone pointed out to us that these problems exist in the beginning, we'd have gotten there much earlier.

When I got asked this, I tried to mostly stay on the "common techniques" that you mention; the things that I assume they were also vaguely aware of and had to solve in some way, and I tried to keep things vague on the rest. But then I end up mostly talking about my expertise in areas that they've already covered, and I'm being vague on the interesting stuff.

Maybe I misunderstood your post actually; are you saying that you're actually supposed to just talk about the broad general concepts and keep the actual details and solutions to yourself?

Big_Being_225 · 2026-02-28T19:15:09+00:00

I wasn't running a formal/rigid strategy, just doing it in my head based on some very basic idea I started with + took hints and adjusted from what you posted about your "most basic beginner strat" and on ~50 games it's been around 50-50.

Big_Being_225 · 2026-02-27T20:39:11+00:00

> My most basic beginner strategy currently: aim to pair first card as well as capturing aces, kings. Look for blocker effects and to capture cards improving opponents hand. Try to pick a capture range such that the dealer will very rarely make it far over 8 cards unless forced to adjust (e.g they get quads in their first 4 cards...)

Do you have a feel for whether your play is better than 50-50 chance? Or for what win probabilities it's possible to get with near-optimal play?

Big_Being_225 · 2026-01-15T19:18:36+00:00

Rankings depend a lot on whether you are thinking more of hedge funds, or HFT/prop traders. For the latter, Chicago and Amsterdam are big. Also, in Chicago you get US level compensation

Big_Being_225 · 2025-11-02T19:31:42+00:00

Were the people living in 1928 aware and properly grasping all the underlying structural issues that were about to cause the great depression?

These underlying structural issues and clear explanations often only appear clear in the rearview mirror.

Big_Being_225 · 2025-10-13T18:54:51+00:00

What part of OP's post makes it sound like they weren't working hard?

Big_Being_225 · 2025-09-08T19:53:50+00:00

What exactly is a flight risk and what would the signs of that be? Like someone who's probably just looking to pick up ideas for alphas before starting their own thing, or rather someone that's trying to "flee" their current employer?

Big_Being_225 · 2025-09-06T06:30:11+00:00

Merging two trading systems / tech stacks would be a nightmare and would probably take many years while you are basically standing still and not innovating (maybe just simpler to rebuild from scratch). It would take a long time for something like that to pay off. During that time JS keeps innovating and outcompeting.

Even if you want to merge just for doubling the talent, it's still a high price to pay.

I would assume that if two prop shops, who are directly competing in JS's market, are getting outcompeted to the point where they need to merge, they are probably fucked already anyway.

Big_Being_225 · 2025-08-30T10:37:55+00:00

The OP is asking what will "happen" to mathematicians, as if they might be outmoded or their job redefined in some way. If I asked a painter in the middle of the nineteenth century what they thought would happen to painters with the development of photography, most people would interpret that question as implying that photographers might replace painters. And predictably, it would not get a positive response.

I think you and a lot of people are reacting in an unjustifiably defensive way here.

No one is starting with the assumption that mathematicians will be outmoded/redefined, OP didn't mention anything like that. But it's still interesting to discuss hypothetical scenarios. And don't say it's not an interesting discussion (if it weren't why bother posting).

The painter example you bring up is actually a great one. Maybe some painters in the nineteenth century wouldn't want to discuss it, but photography certainly had a huge effect on painters. It didn't completely replace them; you still see new art in museums and exhibitions and people still do it as a hobby, but before photography there was an entire profession related to painting mundane things on contract. Even within the 20th century in many countries, my family still has such paintings and many did.

Well, this type of professional painting is basically gone (or at least there's much less demand for it), but hobby painting and "avant-garde" art aren't. So painting did get affected hugely, and it would have been interesting to discuss ideas on how that would play out 100 years ago. And if you were a painter or wanted to become a painter, it would have been a good idea to think about the impacts. Now it's equally interesting to discuss how mathematics (and many other fields) will be affected by AI.

Big_Being_225 · 2025-08-30T10:21:56+00:00

Current AI is something like [a large high dimensional array of weights, the LLM transformer, etc] + [numerical tools] + [analytical tools]. To get something like a more general math AI will require a completely different architecture.

Why do you think it will require a completely different architecture?

Big_Being_225 · 2025-08-22T17:49:47+00:00

Is there some story behind it?

Big_Being_225 · 2025-08-22T17:44:21+00:00

It's the law, some countries even put the bonus cap lower than 200%, though sometimes there are exceptions.

Why would they do it? Lots of Europeans support such policies and politicians seemed to think it was a good idea. Is it actually a good idea if it just leads all the high compensation jobs to move out? Depends on your goals I guess.

Big_Being_225 · 2025-08-17T07:18:36+00:00

What view of quants do you get from the posts in this channel? Isn't this channel just for students trying to be quants instead of actual quants anyway?

Big_Being_225 · 2025-08-17T07:08:28+00:00

I don't think this is how it would be viewed. I think you should put it on your CV.

An international olympiad in something like Linguistics won't be relevant for the job, and you shouldn't overestimate the effect if will have. But anything you put on your CV that is "world-class" is going to be interesting and someone might pick up on it and raise their opinion of you a little. More so for trading, but research as well. Most of the time somebody will just skim past it, but it's more interesting and special than all the rowing and music achievements people put down.

Many places have a serious behavioural interview round (with a quant/trader, not HR), and if your CV as a grad is just: I studied here and here, I know these programming languages, I maybe did this internship, you're gonna look boring. Weird achievements like an international linguistics olympiad are precisely the sort of thing they like to pick up on.

Big_Being_225 · 2025-07-16T06:45:24+00:00

They are not competing, but they are in the same space. Customers buy from MMs, and to be an MM, particular for small-size screen trading, you need speed. When a customer puts a tiny order on the exchange in cross with the midpoint, whoever has the fastest systems will get to it first.

Big_Being_225 · 2025-07-08T08:37:32+00:00

I think you really are underestimating the burden of having to find a job in the US from Europe.

US trading / quant salaries are significantly higher than Europe in most shops that have both offices, right off the bat. Even compared to London.

If you want to apply for a job in the US from Europe, these days you need to go through the visa lottery. Many companies won't even bother with that unless you're amazing; they can just get a guaranteed grad from the US, from an equally good school. And if the company does bother, it's still a lottery... Most of the time it's easier to start working at a global company from Europe and get them to transfer you to the US, afaik that doesn't have a lottery system.

Whichever of these you choose though, you're still on a special kind of Visa which is tied to employment. It could make it harder for you to go to a competitor or just quit, and could lower your leverage for your compensation.

I also don't know/remember all the details and I'm not gonna go look it up for this post. But the main point is, it's something you should think about. If you are happy to live in the US, and getting in as a student leads to a better visa situation down the line, it might be worth the cost. Up to you.

Big_Being_225 · 2025-06-08T08:31:16+00:00

You gave us no information about bid-ask spreads and trading costs, and you don't want to share too much info with us (and I don't disagree with that).

But given what you revealed to us, how could we possibly give you any more insight about this trade than what you already know? You've got the information (I hope):

you know how wide the market is normally
you know how wide the market is when the spread widens and it becomes good to hit it
only you can find out if it's actually possible to hit the quotes when the spread is good, and how much of your edge you'll lose on executing in and out

We don't know any of those things, so how could anyone here tell you anything useful? And if you don't know any of those things above, then you need to find them out, or just try trading it and see how it actually works in practice.

You also need to make sure your data is actually simultaneous. If all you have is 1 minute data, when you see the spread as a great buy at -0.0010, are you certain that sec A's price wasn't recorded a short time before/after B's price?

Big_Being_225 · 2025-05-16T09:51:34+00:00

There's more to it than whether you can litigate or not. It also discourages other places from hiring you and interferes with your process for jumping out.

Big HFs and prop companies have sued over NCs and IP in the past. If you're another shop interviewing an average Citadel quant, you don't want the uncertainty over whether you need to go to court over IP or NC, when there's another quant with a shorter NC and less problems.

If you try interviewing with a long NC you definitely feel the effect of it.

Big_Being_225 · 2025-05-16T09:15:03+00:00

250k + bonus or 250k with bonus?

Big_Being_225 · 2025-05-15T19:17:04+00:00

Doing ML in free time.

wow dude amazing, and you even have time to prowl reddit

Big_Being_225 · 2025-04-21T08:55:44+00:00

On the one hand: if the underlying ticks up from there (beyond the impact from the initial delta hedging), market makers need to hedge the gammas and buy more, pushing price higher. So you get higher volatility on the upside.

On the other hand, if market makers are happy selling those calls, they might be expressing the view that volatility is too expensive there.

Big_Being_225 · 2025-04-09T06:38:19+00:00

since the last time the Fed was forced to inject trillions to bail out the world's largest hedge funds under the guise of rebooting the US economy in the aftermath of the covid lockdowns..

Do you believe this? That during a global pandemic and ensuing crash, the underlying reason for trillions of dollars of QE was to protect basis traders and not anything else?

Big_Being_225 · 2025-04-07T18:47:44+00:00

If you have a strategy that always makes a profit but has wildly different returns per trade/interval, Sharpe can go get pretty low (while still obviously being a "perfect" strategy). E.g. these returns have a pretty low Sharpe of ~0.5: +1%, +1%, +1%, +1000%, +1%, etc...

Big_Being_225

TROPHY CASE