The Idiot's Guide to High Frequency Trading

http://blogmaverick.com/2014/04/03/the-idiots-guide-to-high-frequency-trading/

by jerryhuang100 • 12 years ago

149 93 12 years ago

tptacek13• 12 years ago

If HFT GUARANTEES profits, why are the profits to HFTs declining so sharply, and why do HFT firms make such a small fraction of what the buy-side firms make?

Much more discussion here:

https://news.ycombinator.com/item?id=7531429

ajtulloch• 12 years ago

I think the somewhat sparse academic research on this topic is quite interesting - "The High-Frequency Trading Arms Race: Frequent Batch: Auctions as a Market Design Response" by Budish et. al at Chicago (http://faculty.chicagobooth.edu/eric.budish/research/HFT-Fre...) is one such paper.

The key results in this paper are that:

- market correlations 'predictably' break down at high-frequency horizons

- these correlation breakdowns create a winner-takes-all speed arms race to exploit these opportunities

- a theoretical model can be built to explain the investment in speed as a function of these opportunities

- this model reduces to the prisoner's dilemma from game theory

- the equilibrium state of this model is an environment higher spreads and thinner markets than is socially optimal (without the arms race).

It's a very interesting and readable paper, peppered with interesting market observations and theoretical insights.

001sky12• 12 years ago

Along these lines, a note on so-called latency arbitrage:

http://web.eecs.umich.edu/srg/wp-content/uploads/2013/02/ec3...

But in a study last year, University of Michigan professor Michael Wellman and I developed a model across two exchanges. We examined a strategy called latency arbitrage, which utilizes advantages in access and response time to exploit price disparities caused by fragmentation across those dozens of competing venues. HFTs employing latency arbitrage examine current market information to predict immediate price movements, essentially computing the best prices available before the exchange has even had a chance to update its price quote.

What we found may be even scarier than Lewis's book-selling punchline: it's not simply a matter of the HFT crowd taking profits away from regular investors. Predatory strategies like latency arbitrage have the potential to reduce trading gains for all market participants – high-frequency traders and Average Joes alike.

Their solution was to go to periodic call structure.

mayukh2• 12 years ago

Declining profitabilities caused by increased competition. What market risk are the scalp-style of hft strategies (not all hft's are scalping) taking ? If they can cancel orders at abandon and make pennies if they win the race (against other hft's), but can simply x out of their order if the price doesnt go their way is as close to a riskless profit as it gets.

virtu's prospectus as a case in point. https://www.sec.gov/Archives/edgar/data/1592386/000104746914...

lrm24214• 12 years ago

Manoj Narang of Tradeworx has stated their average holding time is up to 10 minutes. Is he taking risk?

http://washpost.bloomberg.com/Story?docId=1376-N2CB0F6TTDTQ0...

jarrett• 12 years ago

There is still risk. Even if you never lose money on a trade, your firm can lose money. You're paying fixed costs such as colocation. It's conceivable that all your trades are profitable, yet the sum of all those profits is lower than your fixed costs.

That becomes more likely for any given firm as the competition increases. Spreads get smaller; there's more competition for any given trading opportunity. For each firm, that can mean declining profits per trade and declining numbers of trades made. When the product of those two numbers gets too low, you're in the red.

wglb5• 12 years ago

So let's try an experiment to see what happens: https://news.ycombinator.com/item?id=7532584

foobarqux5• 12 years ago

You can "guarantee" profits but still be revenue constrained.

nbouscal• 12 years ago

If you want to know what the actual effects of HFT are on individual investors rather than hypotheticals, a study was done in Canada last year on that exact question. Spoiler alert: HFT is good for the little guys.

http://qed.econ.queensu.ca/pub/faculty/milne/322/IIROC_FeeCh...

dangerlibrary• 12 years ago

1. That paper hasn't been published or peer reviewed.

2. One of the authors used to work for HSBC as a derivatives trader.

3. That study analyzes the impact of a fee-per-order regulatory regime. It is not a study, as you claim, of a world with high frequency traders vs a counter factual world without them.

a8da6b0c91d2• 12 years ago

Some aspects of HFT seem highly analogous to insider trading to me, and insider trading is currently illegal. Abusing the ability to cancel orders fast in order to ping for non-public data about other orders sure seems like an insider advantage. As I understand it this "pinging" is central to HFT strategies. Am I missing something?

lrm24214• 12 years ago

There is nothing about HFT that is analgous to insider trading. Unfortunately the people describing it in public like Cuban simply don't understand what's going on. There is no non-public information at work here.

guelo• 12 years ago

The information that the HFT traders pay millions of dollars to acquire before the rest of the market does is not public at the time that they acquire it by any definition of public that does not include having to pay millions of dollars to acquire the information.

drawkbox• 12 years ago

The whole pinging to cancel seems like it could really end up compounding into problems, it is abuse of a needed cancelation system.

What happens when it spams so much that it triggers other market reactions? (Flash crashes - which seem like it would happen more as more HFT is increased as you don't have the balance of unpredictable individual investors. HFT vs HFT only in the market, who wins?)

What effect does this have on exchange systems bandwidth / capacity / reliability?

Pretty soon every trade one makes will have to fire off 10x the fake orders to stay camouflaged. What happens when HFT DDoS the whole market with fake orders? Right now HFT is trying to fly under the radar but it could get more intense if not checked early at least with some sort of limit. A good market is a fair market, noone wants to start the race a lap back.

HFT skims now but what is in place when HFT decides to take.

snowwrestler• 12 years ago

If they get reactions to their "pings" then by definition the data is not privileged; they're just faster at seeing and reacting to it than other market participants

Insider trading allows someone to plan a course of action prior to other market participants having the opportunity to react.

theorique3• 12 years ago

Complete idiot's guide is right.

Exchanges offer price-time priority. A 'better' price (higher bid, lower offer) gives you priority over a 'worse' price. Given two orders at the same price, an earlier order gives you priority over a later order.

If you spend millions of dollars on computers, data feeds, and salaries to skilled personnel, to predict the motion of markets correctly and work within the system to make money, then you've earned that money fair and square. Companies that don't operate within the rules get shut down fast and hard by the SEC and/or FINRA. This is a highly regulated and policed industry.

HFT is hardly different from Warren Buffett identifying a company with a 10-100 year time horizon. Should we penalize Buffett because he's smarter and better at that game than everyone else in the world? Is he scamming the person from whom he bought shares in 1984?

As Knight Capital showed us two years ago, you can spend those millions, and still screw up and lose $10M per minute for the better part of an hour until your firm is bankrupt. No one is guaranteed to make money.

Posting an order and canceling it is fair game. When the order is in the market, it's a live intent to trade. When it's canceled, it's no longer a live intent to trade. Why is this "moral" when it's a person doing this on a time scale of seconds or minutes, but "fraud on the market" when it's a computer doing it on a time scale of micro or milliseconds? If someone hits that HFT computer's bid, there's an obligation to fill that order - nothing is different about such an order just because it's placed and canceled quickly. The only objection is fear of the unknown. And the only difference here is that it's being done based on an automated strategy, faster than people can react. Your broker has access to HFT tools. Your 401(k) manager has access to HFT tools. If you're a day trader, your order is probably being routed through HFT tools.

kylebrown4• 12 years ago

Why is this "moral" when it's a person doing this on a time scale of seconds or minutes, but "fraud on the market" when it's a computer doing it on a time scale of micro or milliseconds?

Its not always fraud, but some the of tactics get pretty scammy. One highlighted in Flash Boys is a classic bait-and-switch, perpetuated with perverse fee incentives of a "taker rebate" on BATS BYX. I said more here: https://news.ycombinator.com/item?id=7532902

lrm24214• 12 years ago

There's nothing scammy about inverted venues. Those who choose to trade there do so knowing they will get hit first. Buy siders who don't want their brokers to leak information when sweeping should get better brokers. These are professionals we're talking about here. They should have the wherewithal to understand the market they are participating in.

001sky12• 12 years ago

Posting an order and canceling it is fair game. When the order is in the market, it's a live intent to trade. When it's canceled, it's no longer a live intent to trade.

Would you recommend this as advice to YC companies looking to secure VC?

Tactic seems ripe for abuse in M&A negotiations as well.

tptacek13• 12 years ago

Are you genuinely asking someone to make a list of the reasons how a VC term sheet differs from a resting limit order?

theorique3• 12 years ago

No doubt there's an appropriate timescale where the offer is on the table, and also a time after which the offer is no longer on the table. The same is true for job offers, university acceptance, matching with a medical residency, and all sorts of other contracts.

Would it be reasonable for a YC (or other investment) offer to be paired with "decide in an hour or we give it to someone else? Probably not. Would it be reasonable for that timeframe to be a week or two? Probably.

a8da6b0c91d2• 12 years ago

It's more like taking a peek at the other players' cards, when only you have the ability to do that.

We have a bunch of laws that establish the pretense that everybody in the market is equal. I suspect we should get rid of most of the laws and drop the pretense. Folks should participate with the understanding that there are unfairly advantaged operators at all levels. But until that happens it's hard to morally square aspects of HFT.

lrm24214• 12 years ago

No one can see the other players cards in trading unless the player shows them. Brokers sending IOIs to dark pools releases info to the market. Hitting venue A and then venue B in a serial fashion will release info the market, letting some traders cancel before you get to B.

There is no mechanism on the lit markets for anyone to see an order BEFORE it interacts by either posting to the book or being crossed with another order and generating a trade. Anyone who says otherwise is unfortunately misinformed.

dllthomas2• 12 years ago

"It's more like taking a peek at the other players' cards, when only you have the ability to do that."

In what way is it like that?

theorique3• 12 years ago

It's more like taking a peek at the other players' cards, when only you have the ability to do that.

Yes and no. To continue the analogy, if your counterparty checks his cards every few minutes, while you are sitting at the table and monitoring continuously, is that your fault that your decision making strategy has a much tighter feedback loop than his?

In a lot of ways, the HFT practitioners and the portfolio managers (or other active, but infrequent, trader) are playing complementary, but very different games. The portfolio manager wants to move large blocks of stock, and pays for liquidity. The market maker facilitates the motion of large blocks of stock, and charges a premium for assuming the risk of adverse, short-term market movements.

notastartup• 12 years ago

If HFT adds no value, rigs the game, adds cost to everyday investors and traders looking to make an honest fair buck from the markets, will it be allowed in the future?

I almost feel like SEC will come down on them hard.

Basically, I'm bummed at the idea that as individuals, we can't innovate in this field without ponying up several million dollars in startup cost.

lrm24214• 12 years ago

It doesn't cost several million dollars. It does require some capital, likely less than your average valley angel deal. It is not easy and you'll probably fail, but you can certainly try. Phone up Nasdaq, they'll happily give you all you need to know along with pricing information on their website.

jerryhuang100• 12 years ago

SEC might even be part of the ecosystem. According to the book: 1) When the Canadian guy in the book, Brad Katsuyama, went to the SEC for their concern the SEC staffers just shrugged; 2) Since 2007 more than 200 SEC staffers left to work for HFT firms. (Source: Michael Lewis, Flash Boys)

stygiansonic2• 12 years ago

My (non-expert) take: HFT is a tool and it can be used for good or bad. Potential good uses may include: reduction of bid/ask spreads, improved liquidity and faster arbitrage of things like ETFs.

However, it can also be used for bad: http://www.sec.gov/News/PressRelease/Detail/PressRelease/136...

In that link, the SEC charges that a certain firm employed a trading strategy using non-bona fide orders to attract interest on another (bona fide) order. This involved submitting orders on the other side[1] to simulate interest.

HFT makes such strategies viable, or at least more viable.

1. http://www.nanex.net/aqck2/3598.html

EDIT: Corrected to remove inaccurate information.

lrm24214• 12 years ago

The action you link to was not perpetuated by HFT. The vast majority of Lightspeed's business is good ole fashioned screen traders, and that is likely what this was. Previous actions for spoofing and layering were also the result of manual traders using regular day trading tools.

stygiansonic2• 12 years ago

My mistake. I assumed HFT was involved because the timescale of the "layering" orders and subsequent cancellation (following the bona fide order execution) was on the order of several hundred milliseconds.

herbig• 12 years ago

John Stewart had a really interesting interview with Michael Lewis this week about HFT:

http://thedailyshow.cc.com/guests/michael-lewis

jseliger• 12 years ago

Note that this: https://news.ycombinator.com/item?id=7524315 is a better place to start than the linked post.

cgmoore120• 12 years ago

read a great article on this the other night

http://www.nytimes.com/2014/04/06/magazine/flash-boys-michae...

JumpCrisscross2• 12 years ago

The NYSE has always required market makers continuously buy and sell the stocks they specialise in. They must do this in all market conditions, even if it means running a loss. In exchange, they get privileged access to order flow information. This is why those seats are valuable. NASDAQ challenged that model by removing the physical trading floor. Instead of humans standing in a pit there were humans sitting behind screens. But in both cases there is an institution guarding access to the market's nerve centres. Barriers to entry were raised and the incumbents protected.

HFT takes the abstraction one step further. Democratised is that access to privileged order flow - anyone who can pay can get it. Lost is the role of a designated market maker - HFTs can pull out when markets get rough. This is a valid debate.

But don't confuse yourself. The order flow privileges being criticised have always accrued to institutional market makers. It is no surprise that those incumbents are the ones driving the present lobby.

AndrewBissell• 12 years ago

The NYSE requires designated market makers to buy and sell the securities they specialise in. They must do this even in violent market conditions

This "mandate" tended to break down when tested by actual market panics. Bids dried up in 1987, and histories of the 1929 crash often mention clerks and floor runners who entered stink bids at $0.01 for stocks that had recently traded at $30 or $40, and got filled because the specialists had abandoned their posts.

Whether human or computer, market makers know better than to stand in front of a freight train.

JumpCrisscross2• 12 years ago

Market makers can declare "self help" in the event of technical difficulty. Exchange rules prohibit declaring self help to avoid adverse market conditions. In practice, self help declarations have a peculiar habit of cropping up in rough markets. Nevertheless, "guarantors of market liquidity" remains a rallying cry for traditional market makers.

arjn• 12 years ago

Correct me if I'm wrong but couldn't this problem be solved by some simple rules or act of legislation ?

For example, make it a rule that when you buy a stock, you have to hold it for at least some time - say a minimum of 5 minutes.

Or you could just impose a fee/penalty on traders that buy sell the same stock within one day of trading.

(note - I'm merely speculating here and have no specialized knowledge)

tlrobinson• 12 years ago

Is "registering algorithms" really a good solution? It seems incredibly hard to analyze or simulate such a complex system.

njharman• 12 years ago

"With these changes the fastest players were now able to make money simply because they were the fastest traders."

Directly contradicts "speed is not a problem".

Speed directly translates into being able to "front of trades from slower market participants". If they did not have the speed, they could not algorithmically predict the actions of (or react to activity on one exchange before it reaches other exchanges) and jump in front of slower participants.

There's other issues on top of this, such as paying for early or privileged access. But, if you are faster, you can successfully arbitrage across time or distance(really same thing as time)

transfire• 12 years ago

The solution is very simple: a Tobin Tax.

Havoc• 12 years ago

Step 1) Have deep pockets, big balls and the right skills

thikonom• 12 years ago

The title of the article sounds oxymoronic.

arasmussen• 12 years ago

I really wish the "Idiot's guide to high frequency trading" would start out by explaining what high frequency trading is to me like I'm an idiot...

mianos• 12 years ago

Just jump to the second comment for the actual details. Welcome to the internet, where if you are popular you can write any shit you like and people will read it, even if you don't actually know what you are talking about. (I wrote the software that runs some of the major stock exchanges. I did that for 13 years).

asbestoshft• 12 years ago

I have a lot of experience with HFT. Lets clear all of this up.

How exchanges work for dummies.

All of the modern US stock exchanges work as a limit order book. Orders are filled on a price-time basis. In other words, you put in an order, if it isn't filled immediately it gets put in the limit order book with your order going to the end of the line ( lowest priority ) at that price. That's it, that is how it works. Lets look at an example.

I want to buy 250 shares of ABC. Right now there are orders in the book. 5 orders to buy at 9.95, each one for 100 shares. There are also 5 orders to sell at 9.96 also each order for 100 shares. I have several options.

(1) I can put in a market order to buy 250, when this order gets to the order book sell orders will be filled starting with the oldest ones, the ones that have been in the book longest, first. My order will be matched, this is why they call it a matching engine, with two of the sell orders and then a partial on the third one. As orders are filled in the order book messages are sent out to all subscribers of the data that those orders were filled so everyone can keep track of the state of the book. It is important to note that when my order gets to the matching engine/order book there is no chance for the orders in the order book to get cancelled. Those orders aren't told "you are about to get filled do you want to cancel". (2) I can put in a limit order to buy at 9.96 in which case the order will be filled as described in 1 unless the sell orders at 9.96 are cancelled before my order gets to the matching engine. (3) I can put in a limit order to buy at 9.95 in which case my order goes into the order book at 9.95 and I have to wait for the orders ahead of me to either get filled or cancelled and then I have to wait for someone to send in a sell order, either market or limit, that will get matched with my buy order.

That's it! Repeat, all day, every day. OK, that is a lie, there are special order types and that is one way exchanges try to differentiate themselves but that is a simplified way of how this works.

So where is the problem that Brad Katsuyama saw? I don't know him all I know is what I've seen and read. One thing to note is that he talks about buying large blocks of stock. Very large. From http://www.nytimes.com/2014/04/06/magazine/flash-boys-michae... "It used to be that when his trading screens showed 10,000 shares of Intel offered at $22 a share, it meant that he could buy 10,000 shares of Intel for $22 a share." 10k shares at $22k/share, that is $220k in value. So he isn't talking about some small retail order, this is, as he points out, institutional flow.

So lets think about what happens in this kind of case. There are 13 exchanges, all running limit order books. They are geographically disperse and internally they are implemented differently and have different latencies and different message protocols etc. At some instance in time all 13 exchanges have some orders to sell at $22.00. Think about that. In some sense that is awesome. Look how efficient the market is. If you went to 13 gas stations what are the chances that a gallon of regular gas will cost exactly the same at every station? Anyway, back to our problem. You want to buy 10,000 shares. You fire off your order to exchange A to buy 10,000 shares. This hits the matching engine and you get filled on 10,000 shares ( THERE IS NO WAY FOR THOSE SELL ORDERS THAT ARE IN THE BOOK TO BE CANCELLED!!!! The orders in the book aren't sent a message "hey, a 10,000 share order is coming in and about to hit your order do you want to cancel your order first?". THAT DOES NOT HAPPEN!!! ). The thing is that those 10,000 shares that got matched, lets say each order in the book was 200 shares. Your 10,000 share order just took out 50 orders. The fact that these orders were executed is sent out to every data subscriber who is listening for that data. All messages are timestamped, sometimes down to the nanosecond. From that the recipients can tell "wow, all of these 50 orders for 10,000 shares were executed at the same time so that was one order."

Now, if you had orders in at other exchanges to sell at $22 what would your response be? For a second lets think about something more mundane, like TVs. Suppose you work at Target and you have a friend who works at Walmart. You're working one night and a guy shows up driving a semi-trailer. He walks in and says "How many 50 inch flat screens do you have? I'll buy them all, as advertised at $400." You sell all 20 that you have to him. As he's walking out the door he says "Now I'm going to Walmart." Just then your buddy at Walmart texts you and says "what's up? slow night right." and you go "Hell no, just sold 20 50 inch TVs to a guy, he bought everything I had and says he is headed for your Walmart to buy more." Now what does your friend do? In a world where prices are set by supply and demand Walmart could look at that and go "wow, there is a big buyer of 50 inch TVs out there, lets increase our price from $400 to $410." And so that is what Walmart does and sure enough the guy comes in and buys all the TVs from Walmart for $410. Does the TV buyer say the market is "rigged"?

In any case that is very similar to what happens in this case. All of the HFT and market makers see this big order rip through a lot of sell orders at exchange A and they go "wow, there is a big buyer, I better change my sell order from selling at $22.00 to selling at $22.01 or $22.10 or $25 or whatever". Brad Katsuyama looks at that and goes "I've been front run, this market is rigged." And then he has a piece of software written so that all orders arrive at the different markets at the same time, as opposed to leaving his trading workstation at the same time, and suddenly there isn't any front running. There isn't any front running at all, what he is seeing is the reaction to supply and demand.

HFT and market makers live in fear of something called "adverse selection". Market makers are required to post a two sided market, they are supposed to put up a price and quantity that they are willing to both buy and sell at right now. They publish this and they can't back away from it, they have to live up to it if another order shows up to buy or sell at a price that matches they have to execute the trade. The risk to them is that they are trading with someone who has information that they don't have. Just like playing poker or any game, you're going to lose if you play with people who are better than you. In this game though sometimes just having a big order is enough to move the market even if the person behind the order doesn't actually have any new information. Market makers and HFT either want to buy on the bid and sell on the offer and make the spread or they want to do arbitrage. That is how they make money. They lose money if they trade with people who are smarter or faster than they are. As soon as they see big orders come in they get really skittish and so they immediately move their orders to reduce their risk.

I've written a lot and bored almost everyone. Ask away and I'll do my best to answer your questions.

A couple other comments:

1. I'm not saying HFT is good or bad, I don't know. 2. Lots of people mention costs. Just to ballpark the whole thing. For the technology you need to Arista switches, that is $500/port, get a 48 port switch, that is $24k. For servers you need something decent, not crazy, dual CPU, 64 GB, running linux, maybe solarflare for kernel bypass networking, custom software. The hardware will cost you $6k/server. Then you need a connection to an exchange, varies but lets say $10k/month, then you need market data, $5k/month, then you need an order entry port, that is maybe $1k/month. That's it. Well, that is at one exchange, then you need low latency 10 Gbps cross connects between exchanges and you need to do that at each exchange. Then you need to find a clearing firm and you need to become a broker dealer ( exchanges and clearing firms only talk to BDs ). This is a highly regulated environment. You must have a compliance person, you will get audited yearly by SEC, your exchange, FINRA, all kinds of stuff. You will need a serious accountant. You have to have written procedures. 3. And how in the world do you avoid the Knight type of meltdown? Well, when you send in an order the order goes to the exchange. But the exchange also sends the order out via a "drop copy". This might go to your clearing firm so they know you aren't losing tons of money. But you can also get the drop copies and then you can constantly do your own risk checks that your orders you think are open are actually open but the ones you cancelled are actually cancelled. Most exchanges also have "cancel on disconnect" so when you really don't know what is going on you shut off your connection to the exchange and any open orders in the order book are cancelled for you.

The Idiot's Guide to High Frequency Trading

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