The thing I’m most impressed by is that I didn’t see a single LLM wrapper project. In fact I didn’t see a single project that directly involved an LLM at all.
KHRZ · 1h ago
I was curious what kind of company needed to develop all these different kinds of advanced tech. Turns out it's just so they can be sneaky and trade shares quickly. Kind of sad IMO.
MontyCarloHall · 1h ago
Agreed. Amongst the top 5% smartest quantitatively-minded kids I knew in college, I’d say ~25% of them ended up at quant shops like Jane Street, sometimes straight out of school, sometimes after doing a PhD.
I can only imagine what good that brainpower could do for humanity if it weren’t occupied finding cleverer ways to manipulate electronic money.
smokel · 49m ago
They could spend their time playing chess, solving Fermat's last theorem, or invent space weapons. And why stop at humanity?
MontyCarloHall · 24m ago
Perhaps with the exception of space weapons, none of those would pay Jane Street-tier salaries.
All I'm saying is that I wish our economic system were set up such that people with the mental aptitude to work at a place like Jane Street could earn commensurate salaries for applying that aptitude towards problems with much greater positive externalities than proprietary trading. Alas, it is not so.
alchemist1e9 · 12m ago
It’s incorrect that proprietary trading has negative externalities. It’s also exhausting trying to explain that to an audience that has fundamental misconceptions about economics, financial systems, and monetary systems, so I don’t think I have the energy today. Hopefully someone else will and add to this thread.
MontyCarloHall · 9m ago
I never said it has negative externalities (whether it does or doesn't is a totally separate discussion), only that its positive externalities are certainly much less than some other fields that employ commensurately smart people, e.g. healthcare or climate change research.
dude250711 · 37m ago
> I can only imagine what good that brainpower could do for humanity if it weren’t occupied finding cleverer ways to manipulate electronic money.
Maybe humanity can start paying them decent money first?
achierius · 31m ago
You're right, we should fix our economic system so that it better incentivizes things we care about rather than stuff like quant research.
infecto · 5m ago
But what system should we use that fixes our economic system? This is not so much a defense of capitalism but asking what would be a better replacement. Capitalism in my opinion is the best solution so far that helps drive society forward when society is made up of all types of folks with different opinions and views of the world.
Cthulhu_ · 45m ago
Thing is, there's very few problems that don't involve money or making money that can be solved with software. Even laudable projects like green energy are ultimately capitalist endeavours, since nobody will build solar panels etc for free.
nemomarx · 37m ago
Yeah but building stuff to sell is fairly different from making trades faster or other market stuff?
It's another level detached from real value
infecto · 3m ago
How is it different? We could make an argument that the efficient allocation of capital is what drives the rapid expansion of solar. It provides loans for businesses and individuals, it helps investors raise money, it rewards companies for doing well, it allows farmers to hedge crops. It is not perfect but it helps facilitate most of our modern society. Not perfect but which system would be better?
strogonoff · 22m ago
There is a difference between 1) doing something valuable that is then rewarded with money through market mechanics and 2) maximizing money as an end in itself. The former is a great feature of capitalism, the latter is its tragedy and Achilles heel.
In the first case, money is important (if you completely ignore it, you can’t deliver value sustainably), but in a perfect world it should be more like fuel and an indicator that you are doing something right.
infecto · 2m ago
Already said it before but the efficient allocation of capital benefits all of us. From the farmer hedging their crop prices to the local manufacturing company that is drawing a loan to expand their business. What system would you have in its place?
plst · 1h ago
Can someone who actually understands the topic explain to me (or link good resources) why/if what they do is useful to anyone?
Or are they literally just in the business of making money?
(anyone except themselves of course. I'm serious, any hints of irony are unintended)
doovd · 1h ago
It's a common rhetoric from someone who has no clue about financial markets (the person you replied to).
Suppose you want to invest in S&p500 so you want to buy the ETF. Someone like Jane Street can create sell you this ETF, and take care of the risk that comes along with it. For example, the price they sell you this ETF should take into account the pricing of underlying stocks. While it sounds trivial, doing this profitably (and therefore sustainably) is a tough job. And doing it competitively to offer you a good price on it is an even tougher job.
monospacegames · 1h ago
Is that why they got banned in India recently? Because they were too good at offering complex financial instruments to customers at competitive prices?
Ultimately companies like Jane Street have no moral rudder and it is a waste of talent for smart young people to work for them, but we are so far beyond such considerations at this point that it sounds naive to even suggest that maybe talented people should work on things that make society better for everyone and care about the moral implications of their work. Instead everyone is looking for a way to contribute to the coming dystopia in whatever way they can because that's where the money is.
looperhacks · 1h ago
They got banned because they were accused of pretty bad market manipulation (which Jane Street denies of course)
infecto · 1h ago
At the end of the day they are a prop firm. They are a business trying to make money and part of that is market making but it’s not solely market making.
You may not like it but we function in a capitalist society and as such the efficiency of markets is part of that. To have that happen usually requires the market as a whole participating and that includes firms like Jane Street. In the India case I don’t know if what they were doing was illegal or not, India is complicated and the laws there in my opinion are influenced not as much by standards but how well you scratch the itch of others. It is clear the option markets in India was/is highly inefficient in that Jane Street was able to pull the rug over and over. I would be curious who the counter parties were and if this is more about pride of Indian financial institutions not being competent instead of this being illegal. Thinking more about Hindenburg and how India reacted. In the US it feels like a gray area because at the end of the day the options market was clearly clueless on how they should be pricing the options.
Speaking from a US perspective people get thorny on these topics but I think it’s great that folks are always pushing the boundaries. This type of law is tested and we figure out what is ok and what is not. It’s often not cut and dry. Maybe Jane Street was entirely in the wrong in India and they will pay a price. Maybe not. Hopefully their markets learn and benefit from it.
I don’t believe any of us are in a position to say how folks should be spending their time. If we went down that road we could probably argue it back to nobody should be working and should simply be farming for our own food.
whitexn--g28h · 59m ago
The majority of counterparties were regular citizens, who did not understand that what Jane Street was doing was even possible.
Money is debt, you can’t make it without someone else owing it. Taking billions in profits from India’s stock market is pretty straightforward, millions of Indians lost their savings.
infecto · 47m ago
You’re not entirely wrong. India does have a problem with gambling and especially in Bank Nifty. I think something like 50% of options volume is retail, which is wildly high. Just because there is a gambling problem does not make it “pretty straightforward”. The courts will hopefully figure it out to their local pleasing.
Edit: I don’t think my point was clear. If you are going to allow retail in the options market, you should also be ok with sophisticated actors participating in it.
smokel · 37m ago
It would be nice if smart people would not require law to operate in an ethical way. For complicated problems, and for people who are just plain stupid, it's nice to have law and law enforcement, so that capitalist society can work properly.
But the idea that smart people should "push the boundaries" to find out "what is ok and what is not" is either naive or borderline sociopathic IMNSHO.
infecto · 25m ago
I’m not being naive or sociopathic here, I’m pointing out how securities law actually functions, at least in the U.S. It’s rarely as cut-and-dry as you suggest. The courts exist precisely to resolve ambiguity, and there’s always some ebb and flow depending on the administration and the legal environment.
Before throwing around labels like “naive” or “sociopath,” it’s worth recognizing that a capitalist system relies on efficient markets, and efficient markets depend on laws being tested and clarified through the courts. That process benefits everyone.
I’m not making an ethical defense of any specific behavior. I’m saying that just because someone benefits from mispricing in a market doesn’t automatically make it unethical. The courts help define those boundaries. If you reject that premise and prefer a system without capitalism, then we’re simply talking past each other.
And for what it’s worth, tossing out loaded terms like “naive” or “sociopath” isn’t exactly an argument, it’s just lazy rhetoric. It’s ok for us to disagree but why use such a lazy argument?
wyager · 34m ago
Most likely they got slapped in india because a domestic market maker bribed the right regulators and JS did not
Shacklz · 1h ago
> It's a common rhetoric from someone who has no clue about financial markets (the person you replied to).
I think what OP meant is that producing all this fancy advanced tech just to play the financial game isn't all that much benefit for society.
And when looking at societal development in the last couple of decades with the increasing gap in distribution of wealth, social mobility and overall life expectancy declining and other such metrics, I think it's a valid standpoint that maybe, the collective smarts of our society could be allocated a bit better than putting them into companies like Jane Street; as impressive as their work is.
fHr · 1h ago
That is true but capitalism sadly encourages the more profit the better. With making less and less in traditional research jobs for example and rising costs, this positions come more attractive by the second. It is sad to see.
jt2190 · 1h ago
> Or are they literally just in the business of making money?
All for-profit businesses can be viewed abstractly as “in the business of making money”, so this doesn’t really distinguish Jane Street in any way.
> … why/if what they do is useful to anyone?
The utility that Jane Street provides is to the be a persistent buyer and seller of equities. Basically you can call them at any time and buy shares or sell shares. Most shareholders do not trade very often so without a “market maker” like Jane Street it can be a lot of work finding a buyer/seller who is willing to trade on your schedule at the current market price. You’ll have to pay them extra to convince them to trade, which makes it harder to trade profitably. Jane Street significantly lowers the price and makes trading easier (“provides liquidity to the market”).
infecto · 45m ago
I do like this take and one of the reasons I don’t like how many folks pile in on the same theme “these folks are wasting their lives”. We could make the same reductionist conclusion for probably most of the people here on HN.
achierius · 28m ago
Both ad tech and quant work are essentially involuted in that you're spending ever greater amounts of effort and manpower to squeeze out marginal gains because of how much profit doing so provides. Society would not significantly notice or suffer if we spent half as much time on things like this. There are much bigger things we need to do.
dn97 · 1h ago
the premise here is that market makers and arbitrageurs are crucial for efficiently allocating capital. enabling sellers to sell to the highest bidder and buyers to buy from the cheapest vendor means less capital wasted(?)
in my experience Jane Street make no attempt to defend the financial system; such societal benefits are obvious or implicit.
whether you (or they!) really buy that is irrelevant
pedroza_alex · 1h ago
AFAIU the service HFT forms provide to the market is liquidity. Basically allowing you to sell stocks/options as soon as you feel like it.
In turn that leads to more efficient markets since prices converge to their "correct" value faster.
infecto · 1h ago
Market makers or other similar HFT are providing liquidity in an efficient manner to the markets. The benefit is often debated but for the majority of retail and institutional investors, spreads have never been lower. Instead of a guy at the floor swallowing large margins up, you have bots electronically vacuuming pennies.
Of course the whole point for a firm like Jane Street is to make money. To make money means they are competing with someone and that someone could be a loser depending on the scenario.
My own opinion, most folks don’t like market makers or folks who work in financial markets are simply not well informed. The efficient allocation of capital is a valuable service to humans in a capitalist society. People often forget how wide spreads were in the past and that humans were swallowing that margin up with little competition. Now market making is highly competitive and because of it investors both small and large benefit from it.
wyager · 25m ago
I used to work there, so with the appropriate deference to that Upton Sinclair quote about paychecks:
Market makers like JS vastly increase market liquidity across all sectors, which is required for modern high-efficiency economies to work. McDonalds prices are possible because there's enough liquidity in corn futures.
More abstractly, high market liquidity corresponds to higher-confidence information about the future, which hedge funds generate (and distribute for a low fee via markets), allowing for more impressive planning ahead.
Also, you know how when you buy stocks it doesn't cost you anything and you often get better-than-public-book execution prices? That didn't happen prior to modern electronic market makers. Multiply that efficiency gain by umpteen trades every day.
In general, "being in the business of making money" inherently requires you to do something useful to get paid, to the extent you're not just abusing a principle agent problem or something. The most credible argument for hedge funds making money without doing something useful is that they're doing cantillon effect harvesting or something. I think that's pretty small overall.
logicchains · 1h ago
HFTs competing with each other at market making lower spreads; the cost retailers/institutions need to pay to enter a position. Prior to algorithmic trading, you might need to pay a whole percentage point or more (100 basis points), now spreads on the most popular products are so tightly quoted that it can cost less than 1 basis point (0.01%) to enter a position.
rufus_foreman · 1h ago
What use was it to anyone when Gerolamo Cardano devised the rules of probability in order to win at gambling?
PartiallyTyped · 1h ago
Reality is far more sad.
Companies like JaneStreet, 2Sigma, etc employ some of the best software engineers, mathematicians, physicists and what not just so they can
- have better weather forecasts to identify whether a 1 degree delta in South CA can increase oil costs cents on the barrel,
- run pandemic simulations to identify how the spread might happen and where inflation will rise so they move faster,
- track occupancy rates for pharmacies, hotels, casinos, etc via satellite imaging to identify spikes in usage,
- track the tiniest of things like butterfly populations to identify increase in earnings for certain brands of hotels,
- build some of the most efficient software and write their own compilers
all so that they can move money around [and do so quickly].
Finance is not alone either. A non-trivial amount of big tech is on tracking users and serving ads better.
Do I blame the engineers? No.
I am just lamenting the state of society since this is how we have the brightest among us function and work.
wyager · 22m ago
I can construct even more compelling arguments for the uselessness or active harmfulness of most tech jobs.
The only "actually useful" tech jobs if we're going to consistently apply a bar that excludes finance would be stuff like aerospace R&D or ERM systems. Which, to be clear, I would love if society incentivized more strongly. But finance is hardly the worst offender here.
PartiallyTyped · 45m ago
Exercise for the reader; stay a while, and listen.
Once you start noticing things changing, try to identify how you could profit off of it. If it's a change, then there's profit to be made somehow.
Any anecdote is a potential lead.
infecto · 44m ago
Could we not make the same statement for most of the jobs people work here on HN?
achierius · 27m ago
Anyone who works in ad tech, sure.
But plenty of people here do work on real products. Planes need software, browsers need security patches, hell even your accounting app is good value over the days of doing that all by hand.
infecto · 22m ago
Fair, but let’s be honest: even in your accounting app example, the “value” is ultimately in helping a business capture margin more efficiently. That business, in turn, is usually extracting value as a middleman somewhere else in the chain. Same with ad tech, finance, or even a lot of enterprise software, you’re greasing the gears of profit capture, not curing cancer.
That’s not a moral indictment, just a reminder that most of our jobs (mine included) exist to make capital move faster or stickier. Calling one sector “real products” and another “not benefiting society” is a bit of a convenient fiction.
PartiallyTyped · 20m ago
I can't say that about my job; I am providing tools for engineers to use and making things better. As part of my job I am expected to contribute to CPython, and rustc among other things.
infecto · 10m ago
That’s great work, but even there you’re mostly building tools that make other engineers more efficient at building more tools. It’s not that the work lacks value it absolutely does, but it’s still part of the same recursive loop where the ultimate “benefit to society” gets pretty abstract. At the end of the chain, most of those tools are still helping businesses optimize, capture margin, or intermediate in some way.
It’s fine to take pride in craftsmanship, just maybe less fine to pretend it’s immune from the same critique applied elsewhere.
_Algernon_ · 29m ago
Plenty people of here work doing basically the same to maximize the amount of time people, including children and teens, spend staring at rectangular lights to show them ads.
Some amount of extremely competent engineers worked on the tech that made it possible to target beauty ads to insecure teen girls when they deleted a selfie.
Some amount of extremely competent engineers where complicit in building the tech that stoked the fire under the Rohingya genocide.
I could go on, but I think you get the point.
blitzar · 1h ago
People in glass houses shouldnt throw stones. Tech is more parastic.
infecto · 43m ago
While a little harsh I don’t entirely disagree. Depending on your lens, very few of us here on HN are doing something valuable for society.
jvilalta · 40m ago
And of course let's not forget what the most infamous intern of Jane Street wrought!
hackrmn · 1h ago
I've not heard of Jane Street, but looking at the site, it seems they're quite the tech-savvy group for an _asset trading_ company. And reading the article, they apparently "trade" (pun intended) in quite a few different things from CSS to OCaml, which is really nice to see for a place that doesn't directly deal with software as their [business] product (or did I misunderstand their market?).
pjmlp · 1h ago
They are basically the main company driving OCaml development outside INRIA, and the main authors behind Real World Ocaml book (https://dev.realworldocaml.org), which followed up a similar one for Haskell.
tfsh · 1h ago
Jane Street is a technology company first and foremost whose main product is high frequency training, which is similar to mang of these neo-hedge funds (e.g. HRT, Citadel). Which is contrasted to the more established asset managers (e.g. BlackRock, Vanguard, BRK, etc) which I can say from experience are corps tied down in bureaucracy.
JdeBP · 1h ago
If you want to learn about Jane Street:
1. Watch Stand-Up Maths and Numberphile videos on YouTube and do not skip the sponsor advertisement readings, e.g. https://youtube.com/watch?v=eqyuQZHfNPQ .
> which is really nice to see for a place that doesn't directly deal with software as their [business] product
Part of Jane Street's business is HFT, and software is the "product" of HFT firms, because without extremely low-latency software (and hardware) they cannot make money.
throwthrow0987 · 1h ago
How many of these projects are actually merged to master and live though? I noticed the phrase "worked on" a lot, as opposed to shipped.
blitzar · 1h ago
My interns always got very speculative projects, the kind that were low probability of working out so didnt want to waste (more valuable) time exploring. If they ever found anything useful it was 100% reworked from scratch.
My preference was for both sides to learn at the end of the day.
constantly · 1h ago
One of my favorite experiences was that as an intern I shipped what I thought was a useful tool. When I came back full time a year later it had spread and was pretty popular among a subset of the company!
I can only imagine what good that brainpower could do for humanity if it weren’t occupied finding cleverer ways to manipulate electronic money.
All I'm saying is that I wish our economic system were set up such that people with the mental aptitude to work at a place like Jane Street could earn commensurate salaries for applying that aptitude towards problems with much greater positive externalities than proprietary trading. Alas, it is not so.
Maybe humanity can start paying them decent money first?
It's another level detached from real value
In the first case, money is important (if you completely ignore it, you can’t deliver value sustainably), but in a perfect world it should be more like fuel and an indicator that you are doing something right.
Suppose you want to invest in S&p500 so you want to buy the ETF. Someone like Jane Street can create sell you this ETF, and take care of the risk that comes along with it. For example, the price they sell you this ETF should take into account the pricing of underlying stocks. While it sounds trivial, doing this profitably (and therefore sustainably) is a tough job. And doing it competitively to offer you a good price on it is an even tougher job.
Ultimately companies like Jane Street have no moral rudder and it is a waste of talent for smart young people to work for them, but we are so far beyond such considerations at this point that it sounds naive to even suggest that maybe talented people should work on things that make society better for everyone and care about the moral implications of their work. Instead everyone is looking for a way to contribute to the coming dystopia in whatever way they can because that's where the money is.
You may not like it but we function in a capitalist society and as such the efficiency of markets is part of that. To have that happen usually requires the market as a whole participating and that includes firms like Jane Street. In the India case I don’t know if what they were doing was illegal or not, India is complicated and the laws there in my opinion are influenced not as much by standards but how well you scratch the itch of others. It is clear the option markets in India was/is highly inefficient in that Jane Street was able to pull the rug over and over. I would be curious who the counter parties were and if this is more about pride of Indian financial institutions not being competent instead of this being illegal. Thinking more about Hindenburg and how India reacted. In the US it feels like a gray area because at the end of the day the options market was clearly clueless on how they should be pricing the options.
Speaking from a US perspective people get thorny on these topics but I think it’s great that folks are always pushing the boundaries. This type of law is tested and we figure out what is ok and what is not. It’s often not cut and dry. Maybe Jane Street was entirely in the wrong in India and they will pay a price. Maybe not. Hopefully their markets learn and benefit from it.
I don’t believe any of us are in a position to say how folks should be spending their time. If we went down that road we could probably argue it back to nobody should be working and should simply be farming for our own food.
Money is debt, you can’t make it without someone else owing it. Taking billions in profits from India’s stock market is pretty straightforward, millions of Indians lost their savings.
Edit: I don’t think my point was clear. If you are going to allow retail in the options market, you should also be ok with sophisticated actors participating in it.
But the idea that smart people should "push the boundaries" to find out "what is ok and what is not" is either naive or borderline sociopathic IMNSHO.
Before throwing around labels like “naive” or “sociopath,” it’s worth recognizing that a capitalist system relies on efficient markets, and efficient markets depend on laws being tested and clarified through the courts. That process benefits everyone.
I’m not making an ethical defense of any specific behavior. I’m saying that just because someone benefits from mispricing in a market doesn’t automatically make it unethical. The courts help define those boundaries. If you reject that premise and prefer a system without capitalism, then we’re simply talking past each other.
And for what it’s worth, tossing out loaded terms like “naive” or “sociopath” isn’t exactly an argument, it’s just lazy rhetoric. It’s ok for us to disagree but why use such a lazy argument?
I think what OP meant is that producing all this fancy advanced tech just to play the financial game isn't all that much benefit for society.
And when looking at societal development in the last couple of decades with the increasing gap in distribution of wealth, social mobility and overall life expectancy declining and other such metrics, I think it's a valid standpoint that maybe, the collective smarts of our society could be allocated a bit better than putting them into companies like Jane Street; as impressive as their work is.
All for-profit businesses can be viewed abstractly as “in the business of making money”, so this doesn’t really distinguish Jane Street in any way.
> … why/if what they do is useful to anyone?
The utility that Jane Street provides is to the be a persistent buyer and seller of equities. Basically you can call them at any time and buy shares or sell shares. Most shareholders do not trade very often so without a “market maker” like Jane Street it can be a lot of work finding a buyer/seller who is willing to trade on your schedule at the current market price. You’ll have to pay them extra to convince them to trade, which makes it harder to trade profitably. Jane Street significantly lowers the price and makes trading easier (“provides liquidity to the market”).
in my experience Jane Street make no attempt to defend the financial system; such societal benefits are obvious or implicit.
whether you (or they!) really buy that is irrelevant
In turn that leads to more efficient markets since prices converge to their "correct" value faster.
Of course the whole point for a firm like Jane Street is to make money. To make money means they are competing with someone and that someone could be a loser depending on the scenario.
My own opinion, most folks don’t like market makers or folks who work in financial markets are simply not well informed. The efficient allocation of capital is a valuable service to humans in a capitalist society. People often forget how wide spreads were in the past and that humans were swallowing that margin up with little competition. Now market making is highly competitive and because of it investors both small and large benefit from it.
Market makers like JS vastly increase market liquidity across all sectors, which is required for modern high-efficiency economies to work. McDonalds prices are possible because there's enough liquidity in corn futures.
More abstractly, high market liquidity corresponds to higher-confidence information about the future, which hedge funds generate (and distribute for a low fee via markets), allowing for more impressive planning ahead.
Also, you know how when you buy stocks it doesn't cost you anything and you often get better-than-public-book execution prices? That didn't happen prior to modern electronic market makers. Multiply that efficiency gain by umpteen trades every day.
In general, "being in the business of making money" inherently requires you to do something useful to get paid, to the extent you're not just abusing a principle agent problem or something. The most credible argument for hedge funds making money without doing something useful is that they're doing cantillon effect harvesting or something. I think that's pretty small overall.
Companies like JaneStreet, 2Sigma, etc employ some of the best software engineers, mathematicians, physicists and what not just so they can
all so that they can move money around [and do so quickly].Finance is not alone either. A non-trivial amount of big tech is on tracking users and serving ads better.
Do I blame the engineers? No.
I am just lamenting the state of society since this is how we have the brightest among us function and work.
The only "actually useful" tech jobs if we're going to consistently apply a bar that excludes finance would be stuff like aerospace R&D or ERM systems. Which, to be clear, I would love if society incentivized more strongly. But finance is hardly the worst offender here.
Once you start noticing things changing, try to identify how you could profit off of it. If it's a change, then there's profit to be made somehow.
Any anecdote is a potential lead.
But plenty of people here do work on real products. Planes need software, browsers need security patches, hell even your accounting app is good value over the days of doing that all by hand.
That’s not a moral indictment, just a reminder that most of our jobs (mine included) exist to make capital move faster or stickier. Calling one sector “real products” and another “not benefiting society” is a bit of a convenient fiction.
It’s fine to take pride in craftsmanship, just maybe less fine to pretend it’s immune from the same critique applied elsewhere.
Some amount of extremely competent engineers worked on the tech that made it possible to target beauty ads to insecure teen girls when they deleted a selfie.
Some amount of extremely competent engineers where complicit in building the tech that stoked the fire under the Rohingya genocide.
I could go on, but I think you get the point.
1. Watch Stand-Up Maths and Numberphile videos on YouTube and do not skip the sponsor advertisement readings, e.g. https://youtube.com/watch?v=eqyuQZHfNPQ .
1. Read https://news.ycombinator.com/item?id=44480916 .
Part of Jane Street's business is HFT, and software is the "product" of HFT firms, because without extremely low-latency software (and hardware) they cannot make money.
My preference was for both sides to learn at the end of the day.
https://www.cnbc.com/2025/07/04/indian-regulator-bars-us-tra...