Opinion

Felix Salmon

The problems of HFT, Joe Stiglitz edition

Felix Salmon
Apr 16, 2014 00:04 UTC

Never mind Michael Lewis. The most interesting and provocative thing to be written of late about financial innovation in general, and high-frequency trading in particular, comes from Joe Stiglitz. The Nobel prize-winning economist delivered a wonderful and fascinating speech at the Atlanta Fed’s 2014 Financial Markets Conference today; here’s a shorter version of what Stiglitz is saying.

Markets can be — and usually are — too active, and too volatile.

This is an idea which goes back to Keynes, if not earlier. Stiglitz says that in the specific area of international capital flows, “there is now a broad consensus that unfettered markets are welfare decreasing” — and certainly you won’t get much argument on that front from, say, Iceland, or Malaysia, or even Spain. As Stiglitz explains:

When countries do not impose capital controls and allow exchange rates to vary freely, this can give rise to high levels of exchange rate volatility. The consequence can be high levels of economic volatility, imposing great costs on workers and firms throughout the economy. Even if they can lay off some of the risk, there is a cost to doing so. The very existence of this volatility affects the structure of the economy and overall economic performance.

The question is: does the same logic, that traders seeking profit can ultimately cause more harm than good, apply equally to high-frequency trading, and other domestic markets? Stiglitz says yes: there’s every reason to believe that it does.

HFT is a negative-sum game.

In the algobot vs algobot world of HFT, the game is to capture profits which would otherwise have gone to someone else. Michael Lewis’s complaint is that if there weren’t any algobots at all, then those profits would have gone to real-money investors, rather than high-frequency traders, and that the algorithms are taking advantage of unfair levels of market access to rip off the rest of the participants in the stock market. But even if you’re agnostic about whether trade profits go to investors or robots, there are undeniably real-world costs to HFT — costs like drilling through Pennsylvania mountains. As a result, the net effect of the algorithms is negative: they reduce profits, for everybody, rather than increasing them.

In theory, HFT could bring with it societal benefits which more than offset all the costs involved. In practice, however, that seems unlikely. To see why, we’ll have to look at the two areas where such benefits might be found.

HFT does not improve price discovery.

Price discovery is the idea that markets create value by putting a price on certain assets. When a company’s securities rise in price, that company finds it easier to raise funds at cheaper rates. That way, capital flows to the places where it can be put to best use. Without the price-discovery mechanism of markets, society would waste more money than it does.

But is faster price discovery better than slower price discovery? Let’s say good news comes out about a company, and its share price moves as a result — does it matter how fast it moves? Is any particular purpose served to seeing the price move within a fraction of a millisecond, rather than over the course of, say, half a minute? It’s hard to think of a societal benefit to faster price discovery which is remotely commensurate with the costs involved in delivering those faster price moves.

What’s more, faster price discovery is generally associated with higher volatility, and higher volatility is in general a bad thing, from the point of view of the total benefit that an economy gets from markets.

HFT sends the rewards of price discovery to the wrong people.

Markets reward people who find out information about the real economy. Armed with that information, they can buy certain securities, sell other securities, and make money. But if robots are front-running the people with the information, says Stiglitz, then the robots “can be thought of as stealing the information rents that otherwise would have gone to those who had invested in information” — with the result that “the market will become less informative”. Prices do a very good job of reflect ignorant flows, but will do a relatively bad job of reflecting underlying fundamentals.

HFT reduces the incentive to find important information.

The less money that you can make by trading the markets, the less incentive you have to obtain the kind of information which would make you money and increase the stock of knowledge about the world. Right now, the stock market has never been better at reacting to information about short-term orders and flows. There’s a good example in Michael Lewis’s book: the president of a big hedge fund uses his online brokerage account to put in an order to buy a small ETF — and immediately the price on the Bloomberg terminal jumps, before he even hits “execute”. The price of stocks is ultra-sensitive to information about orders and flows. But that doesn’t mean the price of stocks does a great job of reflecting everything the world knows, or could theoretically find out, about any given company. Indeed, if investors think they’re just going to end up getting front-run by robots, they’re going to be less likely to do the hard and thankless work of finding out that information. As Stiglitz puts it: “HFT discourages the acquisition of information which would make the market more informative in a relevant sense.”

HFT increases the amount of information in the markets, but decreases the amount of useful information in the markets.

If markets produce a transparent view of all the bids and offers on a certain security at a certain time, that’s valuable information — both for investors and for the economy as a whole. But with the advent of HFT, they don’t. Instead, much of the activity in the stock market happens in dark pools, or never reaches any exchange at all. Today, the markets are overwhelmed with quote-stuffing. Orders are mostly fake, designed to trick rival robots, rather than being real attempts to buy or sell investments. The work involved in trying to understand what is really going on, behind all the noise, “is socially wasteful”, says Stiglitz — and results in a harmful “loss of confidence in markets”.

HFT does not improve the important type of liquidity.

If you’re a small retail investor, you have access to more stock market liquidity than ever. Whatever stock you want to buy or sell, you can do so immediately, at the best market price. But that’s not the kind of liquidity which is most valuable, societally speaking. That kind of liquidity is what you see when market makers step in with relatively patient balance sheets, willing to take a position off somebody else’s book and wait until they can find a counterparty to whom they can willingly offset it. Those market makers may or may not have been important in the past, but they’re certainly few and far between today.

HFT also reduces natural liquidity.

Let’s say I do a lot of homework on a stock, and I determine that it’s a good buy at $35 per share. So I put in a large order at $35 per share. If the stock ever drops to that price, I’ll be willing to buy there. I’m providing natural liquidity to the market at the $35 level. In the age of HFT, however, it’s silly to just post a big order and keep it there, since it’s likely that your entire order will be filled — within a blink of an eye, much faster than you can react — if and only if some information comes out which would be likely to change your fair-value calculation. As a result, you only place your order for a tiny fraction of a second yourself. And in turn, the market becomes less liquid.

It’s important to distinguish between socially useful markets and socially useless ones.

In general, just because somebody is winning and somebody else is losing, doesn’t mean that society as a whole is benefiting in any way. Stiglitz demonstrates this by talking about an umbrella:

If there is one umbrella, and there is a 50/50 chance of rain, if neither of us has any information, the price will reflect that risk. One of us will get the umbrella. If it rains, that person will be the winner. If it does not, the other person will be the winner. Ex ante, each has the same expected utility. If, now, one person finds out whether it’s going to rain, then he is always the winner: he gets the umbrella if and only if it rains. If the other person does not fully understand what is going on, he is always the loser. There is a large redistributive effect associated with the information (in particular, with the information asymmetry), but no real social benefit. And if it cost anything to gather the information, then there is a net social cost.

HFT is socially useless; indeed, most of finance does more harm than good.

As finance has taken over a greater and greater share of the economy, growth rates have slowed, volatility has risen, we’ve had a massive global financial crisis, and far too much talented human capital has found itself sucked into the financial sector rather than the real economy. Insofar as people are making massive amounts of money through short-term trading, or avoiding losses attributable to short-term volatility, those people are not making money by creating long-term value. And, says Stiglitz, “successful growth has to be based on long term investments”.

So let’s do something about it.

HFT shouldn’t be banned, but it should be discouraged. The tax system can help: a small tax on transactions, or on orders, would reduce HFT sharply. “A plausible case can be made for tapping the brakes,” concludes Stiglitz. “Less active markets can not only be safer markets, they can better serve the societal functions that they are intended to serve.”

COMMENT

I have the feeling Michael Stewart doesn’t believe the ridiculous anti-HFT nonsense in his own book. The entire “controversy” is simply Stewart deciding to amplify an irrelevant bandwagon to stir up the politicians and the ignorati and profit.

Stiglitz is delusional so he might actually believe the nonsense he is spouting here.

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The HFT debate

Felix Salmon
Apr 1, 2014 21:35 UTC

CNBC might be guilty of a tiny bit of hyperbole when they say that their HFT debate today, between the CEOs of rival exchanges IEX and BATS, “stopped trading on the floor of the New York Stock Exchange” and “Twitter stopped too”. Still, they undoubtedly caused a lot of buzz, and the debate — coming, as it does, in the wake of the release of Michael Lewis’s new book on the subject — is an extremely important one, and it is indeed of great interest to that most endangered of species, the NYSE floor trader.

Because CNBC lives on maximizing cacophony, the debate ultimately created more noise than illumination. But at least there was a debate, which is great: it’s very important to get these people talking at the same venue, because if that happens often enough, they might conceivably stop talking at cross-purposes to each other, and maybe even start agreeing on some useful changes which can be made to market structure.

There is the potential for finding common ground here. Brad Katsuyama, the founder of IEX and the hero of Lewis’s book, is no white-hat absolutist: he doesn’t like the way in which the term “HFT” is used to cover a multiplicity of different behaviors, and in fact he is all in favor of computerized trading. (Which makes sense, seeing as how he runs a dark pool.) And BATS president Bill O’Brien is happy to concede that the market has become too complex. He said only that the complexity needs to be “managed”, rather than simplified, but in reality simplification is by far the most effective way to manage complexity. A market with only three or four order types, for instance, is a lot simpler and easier to manage than a market with hundreds.

Can the market be fixed? Michael Lewis says he would like to see that — but at the same time he says that he welcomes the way in which the FBI and the New York attorney general are launching investigations into HFT, to see whether anything in that world can be considered criminal insider trading or market manipulation. My feeling is that if you want prosecutions, then law-enforcement should launch investigations — but that if you really want to fix things, then creating a highly adversarial relationship between HFT shops and the government is not going to help and is in fact almost certain to hurt.

After all, a long sub-plot of Lewis’s book concerns the way in which law enforcement is completely clueless about high-frequency trading, and ends up jailing the innocent rather than doing anything constructive. HFT is very, very hard to understand, and trying to break it down along legal/illegal lines is unlikely to be helpful. If we want to make markets safer both for big real-money investors and in terms of the system as a whole, then the exchanges, along with their HFT paymasters, need to be part of the solution, rather than lawyering up and entering a defensive legal crouch.

And frankly the buy side — which gets a complete pass in Lewis’s book, as the guileless victim — needs to be part of the solution as well. Right now, most investors’ orders are passed to certain broker-dealers not on the basis of which broker offers the best execution, but rather as part of a “soft dollar” system which rewards good research, access to IPO roadshows, and the like. In other words, it’s not traders who decide which brokers to use — it’s portfolio managers.

Most invidiously, soft-dollar fees are paid out of brokerage commissions — which is to say, they’re paid by the investors in the funds. If the system moved to a hard-dollar fee-for-service approach, where traders were incentivized to use the brokers with the best execution, then those fees would be taken out of the management fees which are currently being pocketed by the portfolio managers. And it turns out that portfolio managers are much happier paying commissions out of their investors’ money than they are out of their own income.

All of which is to say that fixing the market will take a lot more than just the FBI coming in with a blunderbuss. It will mean deep reform across a huge swathe of the financial markets, some of it seemingly far removed from HFT. Which in turn means that I’m not holding my breath.

COMMENT

The problem with HFT WHICH everyone is overlooking:
HFT inovolves a lot of CIRCULAR TRADING in between the moments when “real orders” show up, which literally creates/sustains a fake price point. I am NOT convinced of the soundness of price signals in presence of HFT pay for volume games which is a sophist term for circular trading. Entire HFT strategies: Stat Arb, market making etc are irrelevant to absolute price discovery/

They are literally printing the tape like QE prints money in lieu of US Treasuries not having to be repaid on maturity by US govt b/c the fed is returning the principal at maturity back to US gov.

People are bamboozled.

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Michael Lewis’s flawed new book

Felix Salmon
Mar 31, 2014 21:11 UTC

I’m halfway through the new Michael Lewis book – the one that has been turned into not only a breathless 60 Minutes segment but also a long excerpt in the New York Times Magazine. Like all Michael Lewis books, it’s written with great clarity and fluency: you’re not going to have any trouble turning the pages. And, like all Michael Lewis books, it’s at heart a narrative about a person — in this case, Brad Katsuyama, the founder of a small new stock exchange called IEX.

The narrative is interesting enough — but so far I haven’t seen anything that would qualify as the “lighting in a bottle” he promised Boris Kachka. We were promised scoops, but so far it’s hard to see what the scoops are supposed to be. The most interesting thing I’ve discovered so far is the existence of something called “latency tables” — a way for HFT shops to work out exactly which brokers were responsible for which orders. The trick is to realize that because every brokerage is in a slightly different physical location, each house’s trades will hit the various different stock exchanges in a slightly different order. And so by looking at the time difference between a given trade showing up on different exchanges, you can (or could, at one point) in theory identify the bank behind it.

This vagueness about time is one of the weaknesses of the book: it’s hard to keep track of time, and a lot of it seems to be an exposé not of high-frequency trading as it exists today, but rather of high-frequency trading as it existed during its brief heyday circa 2008. Lewis takes pains to tell us what happened to the number of trades per day between 2006 and 2009, for instance, but doesn’t feel the need to mention what has happened since then. (It is falling, quite dramatically.) The scale of the HFT problem — and the amount of money being made by the HFT industry — is in sharp decline: there was big money to be made once upon a time, but nowadays it’s not really there anymore. Because that fact doesn’t fit Lewis’s narrative, however, I doubt I’m going to find it anywhere in his book.

Similarly, Lewis goes to great lengths to elide the distinction between small investors and big investors. As a rule, small investors are helped by HFT: they get filled immediately, at NBBO. (NBBO is National Best Bid/Offer: basically, the very best price in the market.) It’s big investors who get hurt by HFT: because they need more stock than is immediately available, the algobots can try to front-run their trades. But Lewis plays the “all investors are small investors” card: if a hedge fund is running money on behalf of a pension fund, and the pension fund is looking after the money of middle-class individuals, then, mutatis mutandis, the hedge fund is basically just the little guy. Which is how David Einhorn ended up appearing on 60 Minutes playing the part of the put-upon small investor. Ha!

Lewis is also cavalier in his declaration that intermediation has never been as profitable as it is today, in the hands of HFT shops. He does say that the entire history of Wall Street is one of scandals, “linked together trunk to tail like circus elephants”, and nearly always involving front-running of some description. And he also mentions that while you used to be able to drive a truck through the bid-offer prices on stocks, pre-decimalization, nowadays prices are much, much tighter — with the result that trading is much, much less expensive than it used to be. Given all that, it stands to reason that even if the HFT shops are making good money, they’re still making less than the big broker-dealers used to make back in the day. But that’s not a calculation Lewis seems to have any interest in.

In his introduction to the book, Lewis writes this:

The average investor has no hope of knowing, of course, even the little he needs to know. He logs onto his TD Ameritrade or E*Trade or Schwab account, enters a ticker symbol of some stock, and clicks an icon that says “Buy”: Then what? He may think he knows what happens after he presses the key on his computer keyboard, but, trust me, he does not. If he did, he’d think twice before he pressed it.

This is silly. I’ll tell you what happens when the little guy presses that key: his order doesn’t go anywhere near any stock exchange, and no HFT shop is going to front-run it. Instead, he will receive exactly the number of shares he ordered, at exactly the best price in the market at the second he pressed the button, and he will do so in less time than it takes his web browser to refresh. Buying a small number of shares through an online brokerage account is the best guarantee of not getting front-run by HFT types. And there’s no reason whatsoever for the little guy to think twice before pressing the button.

HFT is dangerous, I’d like to see less of it, and I hope that Michael Lewis will help to bring it to wider attention. But my tentative verdict on Flash Boys (I’ll write something longer once I’ve finished the book) is that it actually misses the big problem with HFT, in the service of pushing a false narrative that it’s bad for the little guy.

COMMENT

THE BOOK IS GREAT. MY Best friend worked for Ken Griffin at Citadel, hasn’t read the book, but was practically quoting verbatim many of Lewis’s points. “It’s simply legal front running”. And the liquidity argument, with miniscule bid/offer spreads now, is only true if the prices are real”.

HFTs simply beat your orders into the now numerous exchanges, but activity learned elsewhere, and steal your money by front running you. Just a high tech way of the oldest investment scam known. Now Felix might say, it they only steal a little, your still better off than the old days. Hmmm…

So the big Investment Banks get an excuse to “protect there customers” by channelling their trades into “dark pools”. Then they can front run you themselves with their prop desks! And only sell access to their exchange to only a few HFT firms.

Stealing money is wrong.

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