Here's an excerpt from the book:
When it came to speed, the leading HFT firms invested hundreds of millions of dollars in computers, cable, and telecommunications equipment to ensure they could react first in what was often a winner-takes-all game. Exchanges charged tens of thousands of dollars a month to allow customers to place their servers next to the exchange’s to minimize any lag in receiving data. The result was, in the words of Eric Budish at the University of Chicago Booth School of Business, a “never-ending socially-wasteful arms race for speed.” Only the top-tier firms could afford to keep up, meaning barriers to entry were high. And the exchanges gave their most valued customers sweetheart deals that slashed their cost of trading to a fraction of other participants’. Point-and-click traders had no chance. By the time a human being had seen, processed, and reacted to a buy signal or news of an interest rate cut, the market had entirely absorbed the information and any value had evaporated.
The final element of HFTs’ success was an understanding of the plumbing underpinning electronic markets. The CME’s platform, Globex, is what’s known as a “First In First Out,” or FIFO, market. That means that whenever a trader places a limit order (that is, an order away from the current price), it joins the back of the queue, behind any other orders at that level. If the best bid in the market is currently $99.00 and you want to sell when it reaches $100.00, for instance, your order will be placed last in line behind any other traders currently looking to sell at $100.00.
HFT firms monitor these queues for opportunities to benefit from what is essentially a risk-free option. Consider an example: HFT firm AGGRO decides the market is statistically likely to fall and so places an order to sell ten e-minis at the current price (the “best ask”), again let’s say $100.00. As AGGRO’s ten-lot order makes its way to the front of the queue, new orders join at the same price; by the time AGGRO’s e-minis are purchased, or “hit,” another one thousand lots are waiting in the $100.00 line for a buyer. At this point, there are two possibilities. If the market falls, as AGGRO predicted, the firm can buy ten e-minis at a lower price, say $99.50, and walk away with a profit. If it starts to appear, however, based on fresh information entering the order book, that the price is actually going to rise, AGGRO can quickly turn around and buy ten e-minis from somebody further back in the $100.00 line, exiting the trade without taking a loss. By consummating trades only when they knew they could extricate themselves with little or no loss when they got it wrong, HFT firms largely eradicated losses. They also helped create a situation in which, by 2010, the overwhelming majority of all orders on the CME were canceled before they were consummated.
With all this to-ing and fro-ing, it’s easy to understand how day traders like Nav came to believe they were being targeted. Every time they placed or canceled an order, even if it was only a handful of contracts, the market moved. “I remember clearly the first time I noticed the HFTs,” recalls one of Futex’s senior traders from that era. “It was the start of a new year, we logged on, and the order book just seemed subtly but discernibly different, like an update on your phone or something. I was on a bank of twelve desks and we all just looked at each other and said, ‘What is going on?’ And from then on it became much harder.” At arcades around the world, algos became like bogeymen, blamed for anything and everything that went wrong. If a trader took a position and the market moved against him, it wasn’t a bad trade, it was the “fucking algos picking me off.” Rumors abounded about illicit deals between the exchanges and the HFT giants, but the truth was that the robots didn’t need to know their opponents’ identities to thrive. Fast machines, cheap commissions, and probability were enough.
The ascendancy of HFT squeezed many human scalpers out of the market. Some adapted by trading over longer time horizons, leaving positions running for hours or days rather than seconds. Others took to actively seeking out and trying to exploit algorithms, which quickly became ubiquitous among banks and asset managers as well as HFTs. In 2007, Svend Egil Larsen, a self-described algo hunter from Norway, noticed a flaw in the way an entity reacted to trades in certain stocks and set about taking advantage. He made a modest $50,000 but was later charged, along with a colleague, with market manipulation. The alleged victim in the case was a broker called Timber Hill, one of a raft of companies owned by the Hungarian-born electronic trading pioneer Thomas Peterffy, a man whose personal wealth is estimated by Forbes at $17.1 billion. Larsen was originally found guilty and given a suspended sentence, but the conviction was overturned on appeal. “We feel like Robin Hood, or David beating Goliath,” he told the Financial Times.
Most day traders harbored a degree of resentment toward the HFTs, but for Nav, who had a fierce anti-authoritarian streak, it tapped into something deeper. How could he compete with a bunch of faceless billionaires who never lost? And how was that fair? The markets were supposed to be the ultimate meritocracy. It didn’t matter what you looked like behind your screens, or where your parents came from. If you made the right moves, you got the rewards. Except, Nav was increasingly coming to believe, that wasn’t true. Like so much else in life, the players destined to win were the ones with the most money and the right connections. In reality, Nav didn’t know who his opponents were, and it would later transpire that some of those he complained about the most were actually gifted human scalpers with limited technology just like him. But to his mind, they were all cut from the same cloth: privileged elites with better equipment hell-bent on trying to take him down.
With his math skills, his aptitude for pattern recognition, and his lateral way of thinking, Nav might have made a highly prized employee for an HFT firm. Instead, he made a decision that, as an already successful and wealthy trader, he didn’t have to make. On June 4, 2007, after three years of silence, That’s a Fugazi (Nav's online monicker) filed a new post. It was titled “S&P 500 Futures Corruption,” and it read:
For all those that trade the e-mini S&P 500 with a ladder (where you can see the bids and offers), you must have realized now how some market participants have an unfair advantage over the rest. I’m mainly referring to the two spoofers…who are there everyday and seem to push around the market. Now, I’m not one to complain about spoofing I mean hey it happens in every market, but these two S&P spoofers CANNOT BE HIT. I’ve tried many times gentlemen and they simply can’t. Hence, they contravene the rules, as per CME themselves and should be eliminated from the market…I’ve spoken to CME about this and they simply refuse to accept that it is going on, even though you only need to watch the ladder at any time during the day to see that it is. It’s a clear example of letting the big guys get away wth blue murder at the expense of the small guys.
The post went on to suggest that traders should consider boycotting the e-mini to force the exchange to take action before concluding:
I’m half thinking of asking CME directly how I can get the equivalent software which allows you to spoof without being hit, because I do a fair volume myself, but I feel it would be wrong. THE MARKETS SHOULD BE ON A LEVEL PLAYING FIELD FOR ALL.
Fugazi’s language was less combative than in his earlier posts, but still nobody replied. Four days later, he posted an update:
Oh one final caveat. I am working on a program on TT to get the exact same cheating software. If you cant beat em you may aswell join em eh? Europeans have a pathetic attitude of accepting whatever authority throws at them—they never fight back. With the volume I do I know the exchange will turn a blind eye. And just imagine how easy trading will be since one is already cleaning up whilst playing by the rules. Tis been a sweet week.
There, on a popular public forum, Nav laid out the seeds of a plan that eight years later would culminate in his arrest for manipulating the market and helping cause one of the biggest intraday financial crashes in history. If anyone was paying attention, they might have been able to talk him out of it or notify the authorities. But, like the boy who cried wolf, he’d run out of credibility