Hacker News new | ask | show | jobs
by eulgro 1775 days ago
Whenever I hear about Jane Street and other such trading companies I wonder what do they bring of value into the world. It seems they're basically just working on increasing economic equalities.
7 comments

Are you interested in a genuine discussion on this topic or have you already made up your mind?

For those genuinely interested, for the most part trading firms employing quantitative and automated strategies look to keep the price of derivative or correlated assets in line with their underlying securities.

For example a stock ABC might either directly or indirectly represent two other underlying stocks FOO1 and FOO2 and a trading firm will create a model to determine the relationship between ABC, FOO1 and FOO2 so that ABC = f(FOO1, FOO2).

The role of trading firms then is to compete both on coming up with an accurate model (one firm might believe that the relationship is really ABC = f(FOO1, FOO2) while another firm models the relationship as ABC = g(FOO1, FOO2) and yet a third firm models the relationship as ABC = h(FOO2, FOO3) for some third asset FOO3) as well as premium (a firm will trade ABC = f(FOO1, FOO2) + small_fee and pocket that fee), as well as engineering aspects such as identifying cheaper costs to trade, providing fast execution etc etc...

In the absence of efficient trading strategies or market makers whose job is to maintain this price, what you get is ABC will trade at a huge spread and trades will cause the price of ABC to fluctuate significantly. Both of these properties are vaguely lumped together and called "liquidity" so that trading firms are said to provide liquidity to the market. They ensure that ABC is available to buy and sell at all times at a price that reflects its actual value at every moment in time.

If there's some kind of economic inequality created by keeping the price of assets tightly coupled to one another so that their price reflects their actual underlying value then you are welcome to take some time to present that argument.

From my point of view having done this now for close to 15 years, I find it to be a very interesting and challenging career that lets me consolidate knowledge from a variety of different fields. I get to study and put to use knowledge of many areas of computer science from machine learning, graphics/data visualization, compilers, databases, computer architecture, networking, as well as other fields such as physics, economics, law. I feel very privileged to be able to work in a multidisciplinary field and be able to see almost in real time the effect of my work. I worked as a software developer at Microsoft and Google prior to this and while those were both comfortable and pleasant places to work, it didn't compare in terms of feeling like you had an actual impact on anything. I felt at both of those companies like I was being paid a lot of money to do basically menial jobs.

There is nothing menial about working at a trading firm.

You hit on so many great points in this post. Another important function trading firms (especially market makers like Jane Street) is to serve as ready-and-willing counterparties for the pension funds, endowments, and retirement funds of the world.

All of those firefighters, police officers, and teachers can't get their monthly check unless the pension funds converts part of their investment into cash, and the amount traded gets so large you need well-funded financial participants who will pay the pension fund a large lump of cash and assume the risk of unwinding the position.

The same thing goes for portfolio rebalances. Some smart and prudent retirement fund has run their risk model and decided that their sector exposures are off by like a few percent. They've got 2% too much financials, 2% too little tech, they want to move 1% from consumer staples to consumer discretionary, etc. We're talking about billions of dollars being moved right here! They want to use the money from the assets they sold to purchase the assets they bought, but they want the transaction to happen all at once... not in two parts. Again, this is where the quant funds and market makers of the world come in.

It's easy to think that finance is all fat cats, hedge funds and multibillionaires, but anybody with a retirement plan, a pension, ETF holdings, or mutual fund holdings, benefits from the work these quant funds do.

Just because financial firms provide legitimately important services, doesn't mean the value they capture is commensurate with that value creation.

So yes, it's a leap of abstraction for most people to grasp that 'market making' etc. is an important function, and that there's legit value created.

... but the amount of surplus capture is gigantic and that's the problem.

Fouquet became Louis IX 'CFO' and somehow at the same time amassed massive wealth possibly illegitimately and so he lost his head very quickly.

It's always the people closest to the piles of Gold that end up with all of the Gold. There are a million ways they justify it, and in free markets where information and relations are 'the power', well, they have it all.

Usually it's 'generally very talented' people involved, of that I have no doubt, but that again doesn't justify necessarily the surplus capture.

> It's always the people closest to the piles of Gold that end up with all of the Gold.

Honestly it's a lesson I've taken in my career so far - those who are closest to the money flows get to siphon off the most for themselves. I'm by no means that close, but it certainly informs what I put myself forward for.

Does the difference in skill, effort and output justify it? No, and many of the people working close to the money are no better (or are often far worse) than people further away, being paid less. But people are willing to pay them more, because they are also close to the larger flows of money.

If you count the trading firms that don't do so well, are the people in finance really making off with all that much money, or is it the best firms taking all the sunlight from the middle and worst firms?
Sure, but then you'd have to count the regular businesses that don't post heavy profits of which there are many.

Also either it's 'market making' or 'trading' I think it should never be the same thing under one roof and that market making should have a fair bit of regulation and transparency.

Are you aware of market making actually means?

Because your statement about "either it's 'market making' or 'trading' I think it should never be the same thing under one roof" is like saying "it either gotta be 'playing soccer' or 'kicking the ball', they should not be the same".

Sure, "kicking the ball" is done by many different sports and in many different ways, but it is literally an integral part of playing soccer, so you cannot say "either or" here. The same.

The whole point of market making is trading securities at both ask prices and sell prices, thus providing liquidity to the markets. So they essentially are making profit off bid-ask spread, but doing so reduces bid-ask spread and decreases market inefficiency (thus converging on a more accurate value of the security in question).

And to your point about regulation of market makers, they already have more than just a "fair bit of regulation and transparency".

Look into info about Jane Street and other HTF firms' manipulation of OTC stock prices via dark pools, as well as abuse of the authorized participant status to use the ETF mechanism to naked short sell (not just index arbitrage). The liquidity that's being provided is at the expense of real price discovery and is being used to con retail investors.

If you search for "David Lauer interview", he's a former Citadel HFT that has spoken out about how the funds operating right now are a world away from the platonic ideal of market making you speak to.

I've been in the field for a nearly two decades now, and it's highly recommendable. There's a game-like element that appeals to a certain type of person.

As for doing good in the world, there's an awful lot of businesses that really only contribute via tax. They do something where the entire benefit, sometimes more, is captured between the business and its customers.

But to say it specifically, you need market makers, because if they weren't there you'd have to wait a long time for someone with the opposite intention to you to show up, and that has a huge cost. And keep in mind MMs are only one part of the capital apparatus that we need in the world. This isn't just fluff, I literally had a friend phone me last week looking for money for his African startup that has had to turn down business for lack of capital.

The how of it is a long story as well, but quite an interesting one that spans a number of fields. Coding, economics, finance, and so on.

Another practitioner, my 2c on high frequency trading:

1. Market making (providing two sided liquidity in a market), and in general providing liquidity (even one sided) is a real benefit that (some) trading firms provide (e.g. Virtu, but also many proprietary shops).

The market making function solves the time-mismatch between client A who wants to buy now, and client B who would want to sell in 1 hour.

The liquidity provision is what allows, through pay-for-order-flow, retail investors to get the best current price for AAPL through their Schwab app. Not only that, they do not have to worry about the order execution (how long would it take to get filled), and their fees are low or 0 (because someone is paying Schwab for the order flow).

2. A similar, but slightly different trade is what ensures that ETF are priced "correctly". This is also a boon for retail investors.

In order to ensure the ETF price are in line with the price implied by their underlying assets, someone need to do the "index arbitrage" trade. Again, retail gets a nice useful product (e.g. SPY which tracks S&P500) instead of having to buy a lot of stocks (naively, 500).

3. And then there are directional trades, which are basically trying to "arbitrage away" moves in correlated prices. Is there a value in this? Maybe, but it is just accelerating existing trading realities. Someone would have done it anyway.

I am guessing the perception that the industry adds no value is because of stories about the ridiculously low latency number - trade in the blink of the eye, reacting in nanoseconds, etc.

And I tend to agree.

If the exchanges changed the way they matched orders (e.g. instead of First In First Out/time priority ["who came first"]) to a procedure that introduces randomness that eliminated the advantage from nanosecond/microsecond differences, it would make no difference to the world.

The prices would still be "good enough" (no retails participants care if the prices settled within 100 nanosecond, 1microsecond, or 1 millisecond).

So to sum up, does it bring value? Yes, but it does not mean there is no silliness involved.

I personally think it's refreshingly honest to focus on moving a number up and to the right, rather than pretending to "make the world a better place" while the bottom-line is to move a number up and to the right.
Exactly. Trading has a clarity of purpose that I just love: unlike other jobs no one is lying to themselves, no one is claiming to help other people. We know there is only one reason why we work together: to make as much for ourselves and the firm as humanly possible.
Look at how much trading costs have reduced for all investors over the last two decades due to reduce spreads due to automated market making.
they improve ocaml libraries?
In a capitalist economy everyone is working on increasing economic inequality. It seems for simplicity sake the question of what sorts of industry generate value should be separated from a question of whether corporations should be contributing to inequality.